Introduction

The Hebrew text of Ps. 133:3 reads as follows:

כִּ֤י שָׁ֨ם צִוָּ֣ה יְ֭הוָה אֶת־הַבְּרָכָ֑ה

חַ֝יִּ֗ים עַד־הָעוֹלָֽם

Interpreters disagree on the meaning of כִּי. Compare, for example, the following three translations:

For there the LORD has commanded the blessing, life forevermore (ESV, cf. NRSV, NIV, NJB, LUT, ELB, EÜ, ZÜR, NBS, NVSR, NFC, RVR95, BTX4)
Indeed that is where the LORD has decreed a blessing will be available--eternal life. (NET, cf. HFA, S21, NVI)
There the Lord bestows his blessing, life forevermore (NEB, cf. NLT, JPS85, NGÜ, GNB, TOB, BDS, PDV2017, DHH94I)

Some translations, like the ESV, interpret the כִּי as a causal conjunction. Others, like the NET, interpret the כִּי as an asseverative particle. Other translations, like the NEB, do not directly translate the כִּי at all.

Argument Maps

The function of כִּי

The כִּי in Ps. 133:3 could be either (1) a causal conjunction (e.g., 'for' or 'because') or (2) an asseverative particle ('indeed' or 'yes').

Causal conjunction (preferred)

Most of the modern translations we consulted interpret the כִּי as a causal conjunction. The ESV, for example, says, "For there the LORD has commanded the blessing, life forevermore" (cf. NRSV, NIV, NJB, LUT, ELB, EÜ, ZÜR, NBS, NVSR, NFC, RVR95, BTX4).


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[Causal conjunction]: The כִּי in v. 3 is a causal conjunction ('for' or 'because'), grounding something in the preceding discourse.
 + <Ancient versions>: The ancient versions unanimously rendered the כִּי as a causal conjunction.
  + [Ancient versions]: LXX: ὅτι; Jerome: quoniam; Peshitta: ܡܛܠ ܕ; Targum: ארום
 + <כִּי + qatal>: The combination of כִּי and the qatal verb in v. 3 suggests that the psalmist is grounding some previous statement or speech act.
  + <כִּי + qatal in the Psalms>: In the Psalms, the particle כִּי followed by qatal often functions to ground something in the preceding discourse (cf. Locatell 2017 :M:; BHRG §40.29.2 :G:).
   + [כִּי in the Psalms]: E.g., "By the rivers of Babylon we sat and wept when we remembered Zion... for there (כִּי שָׁם) our captors asked us (שְׁאֵלוּנוּ) for songs" (Ps. 137:3, NIV); cf. Psa. 5:11; 6:3, 9; 9:5, 11; 10:3; 12:2; 16:1; 22:9, 17; 25:19-21; 27:12; 28:6; 31:10-11, 18, 22; 40:13; 41:5; 107:9, 16; 116:7-8; 117:2; 120:7; see esp. Pss. 122:5; 137:3.
 + <Psalms ending with discourse causal כִּי>: Several psalms end with a causal כִּי clause that grounds much or all of the preceding discourse.
  + [Psalms ending with discourse causal כִּי]: E.g., Pss. 1; 5; 11.

Asseverative particle

Some translations interpret the כִּי as an asseverate particle, emphasising the content of the following clause in v. 3. The NET, for example, says "Indeed that is where the LORD has decreed a blessing will be available--eternal life" (cf. HFA, S21, NVI).


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[Asseverative particle]: It emphasizes the following statement, "There YHWH has sent his blessing..." #dispreferred
 + <Could still serve as introducing a summary statement>: As per Seidel's suggested structure for several Psalms of Ascent, כִּי introduces a summary statement of the psalm, and can be translated either "for" or "indeed". The content of 3c could, logically, be providing either a reason for the claims and imagery of the psalm, OR it could be a summary of the images (oil + dew = "the blessing of life everlasting") (Seidel 1982 :31-36 :A:) #dispreferred
   + cf. כִּי in Ps. 122, 125, 130, and 132 #dispreferred
 + <כִּי as asseverative>: כִּי sometimes functions as an asseverative particle, meaning 'yea' or 'verily, indeed' (cf. HALOT 470 :L:). 
  + [כִּי as asseverative]: E.g., כִּֽי־מ֥וֹת תָּמ֖וּת יוֹנָתָֽן (I Sam. 14:44, ESV; cf. Gen. 18:20; 42:16; 1 Sam. 2:30; 20:9; Job 6:21; 12:2). #dispreferred
  <_ <Syntactic/pragmatic environment>: Asseverative כִּי occurs mostly in oaths and in the apodosis of conditional clauses. Elsewhere, its existence is dubious (cf. JM §164b :G:; BHRG §40.29.2(4) :G:).

The scope of כִּי

If כִּי is a causal conjunction, then what is its scope? Does it ground (1) the immediately preceding clause (v. 3a), or does it ground (2) the whole discourse (vv. 1-3a, excluding the superscription)?

Preceding clause (v. 3a)

The first option is that the כִּי grounds the immediately preceding clause (v. 3a): "[the dew of Hermon] which flows down onto the hills of Zion." According to this interpretation, the כִּי clause in v. 3 gives the reason why the dew flows onto the hills of Zion.


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[כִּי modifies the immediately preceding clause only] #dispreferred
 + <Connection between "Zion" in 3b with the emphasised "there" in 3c>: If indeed the referent of "there" is "Zion", the very close proximity of the two words (separated only by ki) could suggest a tight connection between the two clauses, with the latter modifying the former. #dispreferred
 - <Logic>: It makes more sense that the כִּי, in the final line of the psalm, would give a reason for the whole psalm's idea (brothers dwelling together is good and pleasant), rather than just for the preceding idea of the dew flowing onto Zion
  + "Dew", as an inanimate object, acts based on laws of nature and physics--not motivated by a "blessing"
  + <Lexical support>: In poetry, שָׁם can point to a spot in which a scene is localized vividly in the imagination (here, the scene of brothers living in unity) (BDB :L:) 
   + [Ps. 14:5 שׁם פחדו פחד there feared they a fear!]

Whole discourse (vv. 1-3a) (preferred)

The second option is that the כִּי grounds the entire discourse up until this point (vv. 1–3a, excluding the superscription). According to this interpretation, the כִּי clause in v. 3 explains why 'brothers dwelling together' (v. 1b) is—like oil (v. 2) and dew (v. 3)—something that is 'good and delightful' (v. 1a).


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[The כִּי modifies all the preceding statements]: Namely, the thesis statement found in v. 1: that it is good and pleasant when brothers live together (in unity). 
 + <Seidel's suggested structure of Psalms of Ascent>: Many PoA follow this structure: 1. A main statement; 2. A reflection on that statement; 3. A summary clause introduced by כִּי or הנה (Seidel 1982:31-36 :A:).
  + Psalm 133: 1. Main statement, v. 1--"How good and pleasant..."; 2. Reflections, vv. 2-3b--imagery comparisons of oil and dew; 3. Summary statement, v. 3c--"for YHWH sent his blessing..."
 + <Logic>: The "ki" giving a reason for the rest of the psalm makes more sense than for just the immediately preceding assertion (that the dew runs down onto the hills of Zion). 
  <_ <The emphasis on "there">: The Hebrew macrosyntax puts an emphasis on "there" in 3c. If "there" indeed refers to Zion, the very close proximity of "there" to "Zion" could hint that the two clauses are closely linked. #dispreferred
 + <Anderson-Forbes phrase marker analysis>: This semantic clausal-relations resource analyzes the כִּי clause as being subordinate to the main clause/thesis statement in v. 1
 + <Co-occurrence of צִוָּה and בְּרָכָה>: In the two other co-occurrences of these two words, both indicate the result of obedience. 
  + [Lev 25:18,21; Deut 28:2,8]
 + <Psalms ending with discourse causal כִּי>: Several psalms end with a causal כִּי clause that grounds much or all of the preceding discourse (cf. BHRG §40.29.2 on Ps. 1 :G:).
  + [Psalms ending with discourse causal כִּי]: E.g., Pss. 1; 5; 11.

Conclusion

While both the causative and asseverative readings of ki are plausible and sensical in this context, evidence leans slightly in favor of the causative reading, which is why we've rendered 133:3c as "For there YHWH has sent the blessing of life everlasting." We've made this its own statement, following a full stop, because it seems that the ki is providing grounds or reason for all the previous statements in the psalm, not just the clause immediately preceding it. (Our grammar diagram has the ki modifying the main clause of v. 1, which serves as the thesis statement for the psalm.) Modern translations that omit the ki entirely actually seem to support this understanding of ki as well--as a causative modifying, or giving grounds/reason for, all the previous statements--because often the ki is untranslated in this usage, as per BHRG.
This is important because as with Psalm 1, this final ki statement shapes the understanding of the psalm as a whole, by providing a reason for all the other statements in the psalm, especially the thesis statement. Why is it good and pleasant when brothers live together (in unity)? Because when and where they do, God sends his blessing.

Research

Translations

Ancient

LXX: εὐλογήσει σε κύριος ἐκ Σιων ὁ ποιήσας τὸν οὐρανὸν καὶ τὴν γῆν.†

for there, the Lord commanded the blessing, even life for ever.

Peshitta: ܐܝܟ ܛܠܐ ܕܚܪܡܘܢ ܕܢܚܬ ܥܠ ܛܘܪܐ ܕܨܗܝܘܢ ܡܛܠ ܕܬܡܢ ܦܩܕ ܡܪܝܐ ܒܘܪܟܬܐ ܘܚ̈ܝܐ ܥܕܡܐ ܠܥܠܡ

because there LORD JEHOVAH commanded the blessing and the Life unto eternity.

Targum: היך כטלא דחרמון דנחית על טורי )דציון( ארום תמן פקיד יהוה ית ברכתא חיי עד עלמא׃

For there the Lprd has commanded the blessing and life for evermore.

Jerome: sicut ros Hermon qui descendit in montes Sion quoniam illic mandavit Dominus benedictionem et vitam usque in saeculum

For there the Lord hath commanded blessing, and life for evermore.

Modern

כִּי as causal

ESV: It is like the dew of Hermon, which falls on the mountains of Zion! For there the LORD has commanded the blessing, life forevermore.

NIV: It is as if the dew of Hermon were falling on Mount Zion. For there the LORD bestows his blessing, even life forevermore.

NRSV: It is like the dew of Hermon, which falls on the mountains of Zion. For there the LORD ordained his blessing, life forevermore.

NJB: It is like the dew of Hermon falling on the heights of Zion; for there Yahweh bestows his blessing, everlasting life.

Luther 2017: wie der Tau, der vom Hermon herabfällt auf die Berge Zions! Denn dort verheißt der HERR Segen und Leben bis in Ewigkeit.

ELB: Wie der Tau des Hermon, der herabfließt auf die Berge Zions. Denn dorthin hat der HERR den Segen befohlen, Leben bis in Ewigkeit.

EÜ: Es ist wie der Tau des Hermon, der niederfällt auf die Berge des Zion. Denn dorthin hat der HERR den Segen entboten, Leben bis in die Ewigkeit.

ZÜR: Wie der Tau des Hermon, der herabfällt auf die Berge Zions. Denn dort gewährt der HERR den Segen, Leben bis in Ewigkeit.

NBS: C'est comme la rosée de l'Hermon qui descend sur les montagnes de Sion ; car c'est là que le Seigneur assigne la bénédiction, la vie, pour toujours.

NVSR: C'est comme la rosée de l'Hermon, Qui descend sur les montagnes de Sion ; Car c'est là que l'Éternel donne la bénédiction,La vie, pour l'éternité.

NFC: C'est comme la rosée qui descend du mont Hermon sur les montagnes de Sion. Car c'est là, à Sion, que le Seigneur donne sa bénédiction, la vie, pour toujours !

RVR95: como el rocío del Hermón, que desciende sobre los montes de Sión, porque allí envía Jehová bendición y vida eterna.

BTX4: Como el rocío del Hermon, que desciende sobre los montes de Sión, porque allí envía YHVH bendición y vida eterna.

כִּי as asseverative

NET: It is like the dew of Hermon, which flows down upon the hills of Zion. Indeed that is where the LORD has decreed a blessing will be available--eternal life.

HFA: Es ist so wohltuend wie frischer Tau, der vom Berg Hermon auf die Berge Zions niederfällt. Ja, dort schenkt der HERR seinen Segen und Leben, das niemals aufhört.

S21: C’est comme la rosée de l’Hermon qui descend sur les hauteurs de Sion. En effet, c’est là que l’Eternel envoie la bénédiction, la vie, pour l’éternité.

NVI: Es como el rocío de Hermón que va descendiendo sobre los montes de Sión. Ciertamente allí el Señor envía su bendición, vida para siempre.

כִּי omitted

NLT: Harmony is as refreshing as the dew from Mount Hermon that falls on the mountains of Zion. And there the LORD has pronounced his blessing, even life everlasting.

NEB: It is like the dew of Hermon falling upon the hills of Zion. There the Lord bestows his blessing, life forevermore.

JPS 1985: like the dew of Hermon that falls upon the mountains of Zion. There the LORD ordained blessing, everlasting life.

NGÜ: Es ist erfrischend wie der Tau vom Berg Hermon, der den Berg Zion und seine Hügel benetzt. Wo dies geschieht, hat der HERR seinen Segen versprochen[5] – Leben, das niemals enden wird!

GNB: Das ist wie erfrischender Tau vom Hermon, der sich niedersenkt auf den Zionsberg. Dort will der HERR seinen Segen schenken, Leben, das für immer besteht.

TOB: C'est comme la rosée de l'Hermon, qui descend sur les montagnes de Sion. Là, le Seigneur a décidé de bénir : c'est la vie pour toujours !

BDS: C’est comme la rosée ╵qui descend de l’Hermon sur le mont de Sion. C’est là que l’Eternel ╵accorde sa bénédiction et la vie pour toujours.

PDV: C’est comme les gouttes de rosée de la montagne de l’Hermon, qui descendent sur la colline, sur la colline de Sion. C’est là que le Seigneur donne sa bénédiction, la vie pour toujours.

DHH: Es como el rocío del monte Hermón, que cae sobre los montes de Sión. Allí es donde el Señor envía la bendición de una larga vida.

Secondary Literature

Allen: WBC Vol. 21: V. 3c: Heb. כי is probably emphatic (Keel, FZPhTh 23 [1976] 76 and n. 37) rather than causal, as it is generally taken [...] The last line of the psalm is then generally understood as subordinate to the first, a commendation of family unity as a prelude to divine blessing (e.g., Kraus [1989] 486).

Andersen-Forbes Phrase Marker Analysis: The ki clause is subordinate to the main clause of v. 1.

BHRG:

2. Marks a clause that provides a reason (co-ordinating conjunction)

(i) Provides the reason for a state of affairs by marking the actual reason with כִּי. The causal relation is due to natural laws. כִּי may be translated because.

(ii) Provides the reason for a preceding expression or expressions by marking with כִּי the motivation given by speakers to explain something they have said. The causal relation is thus not due to natural laws but is due to the speaker’s own reasoning. כִּי can usually also be translated for.

c. Speakers motivate a whole argument or series of statements by means of כִּי. In such cases translators are inclined to leave כִּי untranslated because it does not entirely make sense on a grammatical level. In Ps. 1 the psalmist gives the reason in verse 6 for what is said in verses 1-5. In this way the psalmist provides evidence for the assertions made in verses 1-5.

In cases where it is clear that speakers consider the grounds on which they base their motivation are difficult to contest, thus suggesting the force of their conviction, one can translate כִּי ‘in fact, the fact of the matter’.

5. Functions as a modal word (Cf. §41.3/9.) כִּי expresses confirmation (primarily in a context of swearing an oath). In these instances it may be translated indeed, truly, surely.

Jouon-Muraoka 2003: In some cases what follows כּי is not a logical cause of an event or circumstance, but evidence of, or an argument, for the preceding assertion: 1Kg 1.24f.

Oswalt 1999: Asseverative usage of ki is not as frequent as the causative usage.

References

Allen, Leslie C. Psalms 101–150 (Revised). Vol. 21. Word Biblical Commentary. Dallas: Word, Incorporated, 2002.

Andersen, Francis I., and A. Dean Forbes. The Hebrew Bible: Andersen-Forbes Phrase Marker Analysis. Bellingham, WA: Logos Bible Software, 2009.

Joüon, Paul, and Takamitsu Muraoka. A Grammar of Biblical Hebrew. Pontificio Istituto Biblico, 2003.

Merwe, Christo Van der, Jackie Naudé, Jan Kroeze, Christo Van der Merwe, Jackie Naudé, and Jan Kroeze. A Biblical Hebrew Reference Grammar. Electronic ed. Sheffield: Sheffield Academic Press, 1999.

Oswalt, John N. “976 כִי.” In Theological Wordbook of the Old Testament, edited by R. Laird Harris, Gleason L. Archer Jr., and Bruce K. Waltke. Chicago: Moody Press, 1999.

Seidel, H. "Wallfahrtslieder." Das lebendige Wort 65 (1982):31-26.

133:3

The Function and Scope of כִּי in Ps. 133:3