Genesis 18:2-3, 8

So he lifted his eyes and looked, and behold, three men were standing by him; and when he saw them, he ran from the tent door to meet them, and bowed himself to the ground, and said, “My Lord, if I have now found favor in Your sight, do not pass on by Your servant.

So he took butter and milk and the calf which he had prepared, and set it before them; and he stood by them under the tree as they ate.