Please, let a little water be brought; wash your feet and rest under the tree.
The Ohr Hachaim first explains the possuk simply, that although he knew they were Mal’achim, Avraham did not wish to change his custom, and he offered them water to wash off the sand that the Arabs used to worship. He would always offer ‘a little water’, to show that it was no great bother for him, and they should not be embarrassed to accept it from him.
However, the Ohr Hachaim then continues to explain the possuk as a conversation between Avraham Avinu and the Mal’achim. Avraham offered them ‘a little water’. Water is an allusion to Torah, as we find in many places. Torah has a simple explanation and a deeper, inner explanation. The Mal’achim are spiritual beings, but now they dressed themselves in human forms for the purpose of visiting Avraham. As far as the physical Mal’achim are concerned, the body is akin to a foot; the end of the body and the less important part.
Avraham was suggesting to them that they take some of the revealed Torah to purify their feet, which are their bodies that they wore for this occasion.
They should then rest under the tree. Avraham used the definite article ‘the’, to denote that the tree was already known to them. The Torah is called the Tree of life, and he was inviting them to rest under the well-known tree.
He then told them that he would bring them bread. Bread refers to the inner, hidden parts of the Torah. This Torah satiates the entire universe, and he offered them this bread to refresh and satiate themselves.
