Albert Barnes Commentary Psalms 118:1

"Oh give thanks unto Jehovah; for he is good; For his lovingkindness [endureth] for ever." — Psalms 118:1 (ASV)

O give thanks unto the Lord ... - Let others unite with me in giving thanks to the Lord; let them see, from what has occurred in my case, what occasion there is for praise. Every instance of a particular favor shown to anyone is to others an occasion for praise, inasmuch as it is an illustration of the general character of God.

On this verse compare the notes at Psalms 106:1. The language is nearly the same.