John Calvin Commentary Genesis 19:1

"And the two angels came to Sodom at even; and Lot sat in the gate of Sodom: and Lot saw them, and rose up to meet them; and he bowed himself with his face to the earth;" — Genesis 19:1 (ASV)

And there came two angels to Sodom. The question arises, why one of the three angels has suddenly disappeared, and only two came to Sodom? The Jews (with their usual audacity in introducing fables) allege that one came to destroy Sodom, the other to preserve Lot. But from the account of Moses, this appears to be frivolous, because we will see that they both assisted in the liberation of Lot.

What I have previously stated is simpler: namely, that it was granted to Abraham, as a special favor, that God would not only send him two messengers from the angelic host, but that, in a more personal manner, he would manifest himself to him, in his own Son. For (as we have seen) one of the messengers held the primary position, being superior to the others in dignity.

Now, although Christ was always the Mediator, yet, because he manifested himself more obscurely to Lot than he did to Abraham, only the two angels came to Sodom. Since Moses relates that Lot sat in the gate of the city in the evening, many argue that he did so according to his daily custom, for the purpose of receiving guests into his house; yet, as Moses is silent about the cause, it would be rash to affirm this as certain.

I grant, indeed, that he did not sit as idle persons usually do; but the conjecture is no less probable that he had come out to meet his shepherds, in order to be present when his sheep were folded. His courteous invitation, mentioned by Moses, clearly demonstrates that he was hospitable; yet, why he then remained in the gate of the city is uncertain, unless he was unwilling to miss any opportunity of doing an act of kindness when strangers appeared to whom he might offer his services. Further discussion on this point can be found in the preceding chapter, regarding Genesis 17:1.