Psalm 16/Notes/Phrasal.v. 4.145456

• The phrase נִסְכֵּיהֶם מִדָּם is short for "their drink offerings (which are made) of blood" (Radak: נסכיהם שהם מדם; cf. Staszak 2024, 123; cf. KJV, ESV, NRSVue, CSB, NET, NIV, NLT, CEB, NEB). The pronoun suffix their (הֶם) indicates the possessor of the drink offerings, and the prepositional phrase "(made) of blood" (מִדָּם) describes the nature, or substance, of the drink offerings. Instead of wine, these pagan offerings to underworld deities consist of blood.
• The syntactic construction נִסְכֵּיהֶם מִדָּם is somewhat unusual. Instead, we might have expected a three-member construct chain: *נִסְכֵּי דְמָם*. E.g., "their idols of silver (אֱלִילֵי כַסְפּוֹ) and their idols of gold (אֱלִילֵי זְהָבוֹ)" (Isa 2:20, ESV). But such a construction could have been confusing, liable to be misunderstood as "drink offerings of their blood." Furthermore, the use of the phrase מִדָּם makes for alliteration (repetition of consonant sounds) with שְׁמוֹתָם in the previous line: מִדָּם // -מוֹתָם. Thus, to avoid confusion and achieve alliteration, the poet used the phrase נִסְכֵּיהֶם מִדָּם.