Genesis 18:1 | Matthew Henry's Commentary

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, ; 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, .