What does Psalm 42:5 mean?

In this verse the psalmist's memory of joyful worship turns quickly to sorrow, then just as quickly to hope. It is not out of the question for believers like the psalmist to experience inner turmoil. Certainly, the prophet Elijah experienced sorrow when he fled to the Horeb to escape Jezebel's wrath (1 Kings 19:1–8). He complained he was no better than his fathers and therefore he wanted to die (1 Kings 19:4). Even Jesus experienced turmoil of soul as He approached the time of His crucifixion. He said, "Now is my soul troubled. And what shall I say? 'Father, save me from this hour'? But for this purpose I have come to this hour. Father, glorify your name" (John 12:27–28). Later, in the garden of Gethsemane, Jesus told His disciples, Peter, James, and John, "My soul is very sorrowful, even to death" (Matthew 26:38).

However, the psalmist refused to let depression win. He told his soul to hope in God, and he was sure his turmoil would turn to praise of the Lord, whom he trusted as his deliverer. The same rhetorical question, and the same answer, is used at the end of the psalm (Psalm 42:11).

The Hebrew of this Psalm allows for two possible divisions between sentences. Some translations include the first words of verse 6 here; this makes the statement "my salvation and my God." Others connect it to the next paragraph, starting off a new sentence with a phrase such as "Oh, my God, my soul is cast down…" Most modern translations favor the first option; older versions tend towards the second.