John Calvin Commentary Genesis 18:16

"And the men rose up from thence, and looked toward Sodom: and Abraham went with them to bring them on the way." — Genesis 18:16 (ASV)

And the men rose up from thence. Moses again calls those men, whom he had openly declared to be angels. But he gives them the name from the form which they had assumed. We are not, however, to suppose that they were surrounded with human bodies, in the same manner in which Christ clothed Himself in our nature, together with our flesh; but God invested them with temporary bodies, in which they might be visible to Abraham, and might speak familiarly with him.

Abraham is said to have brought them on the way; not for the sake of performing an act of hospitality, as when he had first received them, but in order to render due honor to the angels. For the opinion of some is frivolous, who imagine that they were believed to be prophets who had been banished on account of the word. He well knew that they were angels, as we will see more clearly soon. But he follows them on the way, whom he did not dare to detain.