Matthew Poole and continuators on Genesis 18:8

8 And he took butter, and milk, and the calf which he had dressed, and set it before them, and he stood by them under the tree, and they did eat .

To wit, the choicest parts of the calf.

To wait upon them, as the word standing is used, Nehem. 12. 44. Ier. 52. 12.

Either seemingly, as the Scripture oft speaks of things according to appearance; or really, they received the meat into the bodies which they assumed, where it was consumed by a Divine power.