G‑d appeared to Abraham…but he looked up and saw that there were three men… (Genesis 18:2)

Abraham put aside his encounter with G‑d in order to greet his guests. From this we learn that hosting guests is so great that it takes priority over an encounter with G‑d. (Maimonides, Mishneh Torah)

The three men that Abraham greeted and fed turned out to be angels.

Angels don’t eat or drink. Neither do they need a place to sleep. They only pretended to eat and drink out of respect for Abraham.

If so, what did Abraham accomplish? He served food to beings that never hunger and drinks to beings that never thirst. For this he walked out of a private audience with G‑d Himself?!

Aside from that, how can we learn from his example the greatness of caring for guests when in fact he provided his guests with nothing?

Yet indeed we learn more from this incident than any other.

We learn that the main ingredient of hosting guests is not the food, not the drink, not even the roof over their heads and a comfortable bed.

The crucial ingredient of hosting guests is to show them that you care.

And that, Abraham and Sarah exemplified to perfection.

Likutei Sichot vol. 25, p. 78.