John Calvin Commentary Psalms 145:7

"They shall utter the memory of thy great goodness, And shall sing of thy righteousness." — Psalms 145:7 (ASV)

They shall speak forth, etc. Since the verb נבע, nabang, properly means to gush out, some suppose that, when applied to speech, it signifies not merely speaking but an overflowing utterance, like water rushing from a fountain; and the verb ירננו, yerannenu, at the end of the verse, corresponds to this, meaning to shout or sing aloud.

To celebrate the memory of the Lord’s goodness is the same as recalling what we have personally experienced of his goodness. We cannot deny God’s claim to praise in all his excellencies, but we are most deeply affected by such proofs of his fatherly mercy as we ourselves have experienced.

David, therefore, makes use of this inviting consideration to encourage us to engage more readily and cheerfully in the praises of God, or rather (according to the figurative word already used,) to burst forth in celebration of them.