|Abraham and Sarah (Providence Lithograph Company – Public Domain/Wikimedia Commons)
In Tractate Bava Metzia of the Babylonian Talmud, we find a midrash explaining that the Israelites benefit later on as a result of Abraham’s kindness to these strangers:
Rab Judah teaches in Rab’s name: Everything which Abraham personally did for the Ministering Angels, the Holy One Blessed be God did for God’s children [the Israelites]; and whatever Abraham did through a messenger, the Holy One Blessed be God did for God’s children through a messenger [Moses].
Therefore, just as Abraham ran to the herd to get a tender calf to cook for his guests, a wind from God started up and swept quail from the sea and strewed them over the camp (Numbers 11:31). Just as Abraham took butter and milk, God rained bread from heaven for the Israelites (Exodus 16:4). As Abraham stood by the guests under the tree, God stood before them upon the rock at Horeb (Exodus 17:6). And like Abraham went with them to bring them on the way, God went before the Israelites in a pillar of cloud by day (Exodus 13:21). Finally, Abraham had water fetched for the three men, and similarly God commanded Moses to strike the rock for drinking water to come out of it for the Israelites (Exodus 17:6).