John Calvin Commentary Genesis 17:3

"And Abram fell on his face: and God talked with him, saying," — Genesis 17:3 (ASV)

And Abram fell on his face. We know that this was the ancient rite of adoration. Moreover, Abram testifies, first, that he acknowledges God, in whose presence all flesh ought to keep silence and be humbled; and, secondly, that he reverently receives and cordially embraces whatever God is about to speak.

If, however, this was intended as a confession of faith, we must observe that the faith which relies upon the grace of God cannot be separated from a pure conscience. God, in offering his grace to Abram, requires of him a sincere disposition to live justly and holily. Abram, in prostrating himself, declares that he obediently receives both.

Let us therefore remember that, in one and the same bond of faith, the gratuitous adoption in which our salvation is placed is to be combined with newness of life. And although Abram utters no word, he declares more fully by his silence than if he had spoken with a loud and sounding voice, that he yields obedience to the word of God.