“And the L-RD appeared unto him by the terebinths of Mamre, as he sat in the tent door in the heat of the day; and he lifted up his eyes and looked, and, lo, three men stood over against him; and when he saw them, he rant to meet them from the tent door, and bowed down to the earth, and said: ‘My lord, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant.” – Genesis 18:1-2, JPS 1917 Tanach
The traditional rendering, according to most commentaries is puzzling. The verse reads, “My l-rd, if now I have found favour in thy sight, pass not away, I pray thee, from thy servant” (Genesis 18:3). Most commentators view this request to be addressed to the L-RD from Abraham, asking for His presence to remain, while he attends to his three guests. Yet, a closer reading reveals a more nuanced view: Abraham “prostrated himself on the ground,” and then made his request to the three guests, who were in front of him.
Moreover, the word rendered above as lord, is the Hebrew word, “Ad’nai.” It is first used in the Tanach, when Abraham addresses the L’RD, in regard to his inheritance, inasmuch that he was to be the father of nations, yet, was childless. The word, can mean Master, and indicates Abraham’s acknowledgment of the L’RD as L’rd of his life. When he prostrates, as mentioned above, in front of the three men, who are really angels, he is addressing them at the same level he addresses the L-RD.
“And the L-rd appeared to him. How? Three men who were angels came to him.”
– Rashbam, sefaria.org