Mamre

Genesis 17        "When Abram was ninety-nine years old Y*hw*h appeared to him and said, 'I am El-Shaddai.         Live in my presence, be perfect, and I shall grant a covenant between myself and you, and             make you numerous.' God spoke to him as follows, '... you will become the father of many             nations. I shall make you exceedingly fertile. I shall make you into nations, and your issue will             be kings."
Genesis 18        "Y*hw*h appeared to him at the oak of Mamre while he was sitting by the entrance of the tent         during the hottest part of the day. He looked up and there he saw three men standing near him.         As soon as he saw them he ran from the entrance of the tent to greet them, ... Let me have a             little water brought, and you can wash your feet and have a rest under the tree. Let me fetch a             little bread and you can refresh yourselves before going further ... Then taking curds, milk and             the calf  which had been prepared, he laid all before them, and they ate while he remained             standing near them under the tree ..."
(... only gradually are the three men revealed as angels ...)