Albert Barnes Commentary Psalms 89:17

"For thou art the glory of their strength; And in thy favor our horn shall be exalted." — Psalms 89:17 (ASV)

For you are the glory of their strength - The ornament; the beauty; the honor; that is, their strength derives its beauty and honor not from anything in themselves, but from the fact that it is derived from you. The strength thus imparted is an honor or ornament in itself; it is an honor and glory to them that it is imparted to them.

And in your favor - Or, by your favor, or good pleasure.

Our horn shall be exalted - The horn is a symbol of power. Compare Psalm 22:21, note; Psalms 75:4; Daniel 7:8, note; Job 16:15, note. The meaning here is that their power had been derived from God, or that all that contributed to their exaltation and honor in the world had been derived from him.