The writer suffered at the hands of tormenting enemies. He longed for God whom he confidently expected to be able to praise in the future when the Lord would deliver him.
42:1-2 As water from a brook sustains a deer physically, so God Himself sustains people spiritually (cf. John 4:14). The psalmist was thirsty for God. He could not obtain the refreshment he needed yet, but he looked forward to finding it soon.
42:3-4 Rather than drinking from God he had to drink the water of his own tears. God was not providing for his needs just then. The writer remembered with great delight the times when he found spiritual refreshment at the sanctuary in Jerusalem, but he was not able to return there yet.
42:5 The psalmist encouraged himself rhetorically by reminding himself that he would again praise God. He needed to continue to hope in God till then.
