What does Psalm 42:3 mean?

The psalmist missed the worship of God in the sanctuary so much that he cried heavy tears day and night. There are two possible ways to interpret the metaphor which compares tears to bread. This might mean someone who cries daily, and regularly, as someone might daily and regularly eat food (Matthew 6:11). Another possibility is that the psalmist is upset to the point that he cries, but doesn't eat.

To add insult to injury, the psalmist's enemies mock him. They asked, "Where is your God?" When Jesus died on the cross, He felt the sting of separation from God. He cried out, "My God, my God, why have you forsaken me?" (Matthew 27:46). The chief priests, the scribes, and the elders, the very men who had campaigned for His crucifixion, jeered at Him and said sarcastically, "He trusts in God; let God deliver him now" (Matthew 27:43).

"Where is your God?" was frequently asked of righteous Jews by Gentiles who worshiped false gods (Psalm 115:2; Micah 7:10). Christians, too, may be the target of this question. It's commonly used to challenge the biblical view of God during some tragedy or bizarre circumstance (2 Peter 3:3–4). Of course, God is seated on a throne in heaven, but He also lives in the hearts of those who know Him.