The Rashi

Rashi offers two interpretations of who Avraham was addressing:

And he said, “My lord, if only I have, etc.”—He addressed the leader of the men, and he called them all lords, and to the leader he said, “Please do not pass by,” because if he would remain, his companions would stay with him. According to this version, it (the title “Lord”) is profane (and does not refer to G-d).

Another explanation: It (“Lord”) is holy, and he was telling the Holy One, blessed be He, to wait for him until he would run and bring in the wayfarers... And the two interpretations [of Lord as being profane and holy in this context] are in Genesis Rabbah.