What does Psalm 38:9 mean?

Throughout this psalm, David confesses that he suffers because of his own sin (Psalm 38:1–4, 18). Much of these symptoms are poetic expressions of his guilt and shame: conviction brought by God (Psalm 38:5–8). It's fitting, then, that David chooses to refer to God using the Hebrew term Adōnā'y, or Adonai, which literally means "Master." This term was sometimes spoken when reading Scripture, rather than trying to pronounce God's self-identified name of YHWH. This reference shows that David is humble and regards himself as God's servant.

David also acknowledges that the Lord is omniscient: nothing is hidden from Him. The Lord was fully aware of David's pain and sighs, as well as his motives and his desires. Every believer should derive comfort, peace, and courage from the fact that the Lord knows all about his suffering. Such omniscience does not preclude the need to pray. Hebrews 4:14 tells us Jesus, the believers' great high priest, is available. The same passage assures us He sympathizes with our struggle since He experienced temptation but didn't sin (Hebrew 4:15). This is why we can confidently approach God in prayer, as we seek to "receive mercy and find grace to help in time of need" (Hebrews 4:16).