Psalm 51/Notes/Lexical.v. 8.297895

The meaning of טֻחוֹת is uncertain, both here and in Job 38:36. In Psa 51:8, the most plausible meaning is "covered (places)," based on the root טוח that means to "cover," such as with plaster or paint. In parallel with סָתֻם "closed off," the reference seems to be to areas (of the person) that are invisible and inaccessible except to God. See The Meaning of tukhot and satum in Psalm 51:8.