Albert Barnes Commentary Psalms 72:18

"Blessed be Jehovah God, the God of Israel, Who only doeth wondrous things:" — Psalms 72:18 (ASV)

Blessed be the Lord God, the God of Israel - The God who rules over Israel; the God who is worshipped by the Hebrew people, and who is recognized as their God. They adore Him as the true God; and He is their God, their Protector, their Friend.

Who only does wondrous things - Things that can properly be regarded as “wonders;” things suited to excite admiration by their vastness and power. Compare Exodus 15:11.