Albert Barnes Commentary Psalms 119:174

"I have longed for thy salvation, O Jehovah; And thy law is my delight." — Psalms 119:174 (ASV)

I have longed for thy salvation, O Lord - See the notes at Psalms 119:166. The word rendered “I have longed” denotes an earnest desire or wish. Compare the notes at Psalms 42:1 and Psalms 119:20.

And thy law is my delight - It is so much the object of my delight that I earnestly long or desire to see more and more of its richness and fullness.