Genesis 18:2-3, 8

and he lift up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground, and said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant

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.