And Abraham ran unto the herd, and fetched a calf tender and good, and gave it unto a young man; and he hasted to dress it.

Jamieson-Fausset-Brown Bible Commentary

7. Abraham ran unto the herd, and fetched a calf-Animal food is never provided, except for visitors of a superior rank when a kid or lamb is killed. A calf is still a higher stretch of hospitality, and it would probably be cooked as is usually done when haste is required-either by roasting it whole or by cutting it up into small pieces and broiling them on skewers over the fire. It is always eaten along with boiled corn swimming in butter or melted fat, into which every morsel of meat, laid upon a piece of bread, is dipped, before being conveyed by the fingers to the mouth.

Matthew Henry's Concise Commentary

18:1-8 Abraham was waiting to entertain any weary traveller, for inns were not to be met with as among us. While Abraham was thus sitting, he saw three men coming. These were three heavenly beings in human bodies. Some think they were all created angels; others, that one of them was the Son of God, the Angel of the covenant. Washing the feet is customary in those hot climates, where only sandals are worn. We should not be forgetful to entertain strangers, for thereby some have entertained angels unawares, Heb 13:2; nay, the Lord of angels himself; as we always do, when for his sake we entertain the least of his brethren. Cheerful and obliging manners in showing kindness, are great ornaments to piety. Though our condescending Lord vouchsafes not personal visits to us, yet still by his Spirit he stands at the door and knocks; when we are inclined to open, he deigns to enter; and by his gracious consolations he provides a rich feast, of which we partake with him, Re 3:20.