Genesis 18:4

Let a little water, I pray you, be fetched, and wash your feet, and rest yourselves under the tree:

Let a little water, I pray you, be fetched, and wash your feet,.... Which was very refreshing to travellers in hot countries, who walked barefoot or in sandals; and this he proposes to be done by one of his servants, whose business it was, only desires they would give him leave to order it, 1 Samuel 25:41; and so it was usual in other countries, and in later times, for servants to fetch water to wash the hands and feet of guests {l}:

and rest yourselves under the tree; before the tent door, under which doubtless were seats to sit down upon, where they might rest their weary limbs; it is very probable this was an oak tree, and which, and a turpentine tree the ancient writers speak of, continued unto the times of Constantine, See Gill on "Genesis 13:18"; and the Jewish writers say {m}, that now near the city (Hebron), between the vineyards, are the oaks of Mamre, where is the house of Abraham our father, on whom be peace, and the tree under which the angels ate, and the stone on which he (Abraham) sat when he was circumcised.

{l} "----- dant manibus famuli lymphas." --Virgil. Aeneid. l. 1.
{m} Cippi Hebr. p. 9. Ed. Hottinger.