Charles Ellicott Commentary Psalms 89:1

"I will sing of the lovingkindness of Jehovah for ever: With my mouth will I make known thy faithfulness to all generations." — Psalms 89:1 (ASV)

I will sing. —This lyric purpose soon loses itself in a dirge.

For ever. —The Hebrew (‘ôlam) has properly neither the abstract idea of negation of time, nor the concrete (Christian) idea of eternity, but implies indefiniteness, and looks either backwards or forwards.

With my mouth — i.e., aloud, or loudly.