Moreover, that which St. Augustine has said is true, that no one is able to sing things worthy of God except that which he has received from Him. Therefore, when we have looked thoroughly, and searched here and there, we shall not find better songs nor more fitting for the purpose, than the Psalms of David, which the Holy Spirit spoke, and made through him. And moreover, when, we sing them, we are certain that God puts in our mouths these, as if he himself were singing in us to exalt his glory.

Cited from W. Robert Godfrey “John Calvin—Pilgrim and Pastor”  pp. 75