Psalms 89:1 - The Popular Commentary by Paul E. Kretzmann

I will sing of the mercies of the Lord forever, the poet immediately launching forth into his subject, the theme of his song, the merciful kindnesses of Jehovah; with my mouth will I make known Thy faithfulness to all generations, since it is this attribute, this manifestation of the divine essence, which causes Him to abide by the promises once made to those who believe in Him. The theme is now set forth somewhat more at length.