Sforno, on Gen 18:2

“And when he had lifted up his eyes, there appeared to him three men standing near him: and as soon as he saw them he ran to meet them from the door of his tent, and adored down to the ground.”

“(1) HE LIFTED HIS EYES [JPS: LOOKING BACK]. He intentionally looked. (2) STANDING OVER HIM. Facing him, as if waiting to speak with him when he could look after seeing the major sight. For those who wait to speak to a person are referred to as standing over him, as with (Gen. 45:1), "control himself before all those standing over him [JPS: his attendants]" and as with (Exod. 18:14), "all the people stand about you." (3) HE RAN TO GREET THEM. Before they would approach to speak with him. (4) FROM THE ENTRANCE OF THE TENT. He started from the tent entrance to run out of respect for them, because haste with respect to a matter shows its importance to the one who is hurrying, as with (Exod. 34:8), "Moses hastened to bow low to the ground in homage." (5) HE BOWED LOW TO THE GROUND. Because their appearance was frightening, as it says (Jud. 13:6), "he looked like an angel of God, very frightening," and he thought them messengers of some king.”

Imported from an open dataset — not yet checked against the printed edition.