And the LORD appeared unto him by the oaks of Mamre: and he sat in the tent door in the heat of the day;
All Commentaries on Genesis 18:1 Go To Genesis 18
Ambrose of Milan
AD 397
Abraham, who was glad to receive strangers, faithful to God and tireless in his service and prompt in fulfilling his duty, saw the Trinity typified. He added religious devotion to hospitality, for although he beheld three, he adored one, and, while keeping a distinction of the persons, yet he called one Lord, thus giving honor to the three but signifying one power. For not knowledge but grace spoke in him. And he believed better what he had not learned than we who have been taught. No one had falsified the type of truth, and therefore he saw three but worshiped their unity. He brought out three measures of meal but slaughtered one calf, believing one sacrifice was sufficient, but a threefold offering; one victim, but a threefold gift. On His Brother, Satyrus