Arcana Coelestia # 2186
2186. 'And he stood before them under the tree' means consequent perception. This follows from the meaning of 'a tree' as perception, dealt with in 103, 2163. Above in verse 4 it was stated that the three men who came to Abraham were to recline under the tree, which meant that the Divine was to draw near to the perception of that state which was the Lord's at that time. Here however it is said that Abraham stood under the tree, which means that the Lord drew near to the Divine perception after He had prepared Himself, which is a reciprocal action. Anyone may see that it is not without a reason that reference is made to the three men and to Abraham standing under the tree, and that therefore this detail was included because of the arcana that lie hidden within these descriptions.
Leviticus 7:19-21
19
"'The flesh that touches any unclean thing shall not be eaten. It shall be burned with fire. As for the flesh, everyone who is clean may eat it;
20
but the soul who eats of the flesh of the sacrifice of peace offerings, that belongs to Yahweh, having his uncleanness on him, that soul shall be cut off from his people.
21
When anyone touches any unclean thing, the uncleanness of man, or an unclean animal, or any unclean abomination, and eats some of the flesh of the sacrifice of peace offerings, which belong to Yahweh, that soul shall be cut off from his people.'"
