All this happened, more or less.

And the Lord appeared to him by the terbinth of Mamre, as he sat in the tent door in the heat of the day; and he raised 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 to the ground, and said, My Lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant; let a little water, I pray you, be fetched, and wash your feet, and rest yourselves under the tree; and I will fetch a morsel of bread, and comfort your hearts; after that you shall pass on: seeing that you are come to your servant. And they said, So do, as thou hast said.

..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 ate. And they said to him, Where is Sara thy wife? and he said, Behold, in the tent. And he said, I will certainly return to thee at this season; and, lo, Sara thy wife shall have a son. And Sara heard in the tent door, which was behind him.

another communication experiment. first the angel, now the three men.