John Calvin Commentary Psalms 66:20

"Blessed be God, Who hath not turned away my prayer, Nor his lovingkindness from me." — Psalms 66:20 (ASV)

Blessed be God! who has not turned away my prayer. He concludes the psalm, as he began it, with thanksgiving, and gives the reason for his not having been repulsed; or, using the figurative expression he employs, for God’s not having turned away his prayer. This was because he had not withdrawn his mercy. For it is entirely of his free grace that he is propitious, and that our prayers are not wholly ineffectual.