Genesis 17:3 - Joseph Benson’s Commentary on the Old and New Testaments

And Abram fell on his face while God talked with him Either, 1st, As one overcome by the brightness of the divine glory; as Daniel and John also were. Or, 2d, As one ashamed of himself, and blushing to think of the honours done to one so unworthy. He looks upon himself with humility, and upon God with reverence; and, in token of both, falls on his face.