Albert Barnes Commentary Psalms 109:30

"I will give great thanks unto Jehovah with my mouth; Yea, I will praise him among the multitude." — Psalms 109:30 (ASV)

I will greatly praise the Lord with my mouth - I will sing abundant praises to him. Compare the notes at Isaiah 38:20.

Yea, I will praise him among the multitude - In the great congregation. I will publicly acknowledge his goodness and mercy. See the notes at Psalm 22:25.