And he lift up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground, Three men stood by him - נצבים עליו nitstsabim alaiv, were standing over against him; for if they had been standing by him, as our translation says, he needed not to have "run from the tent door to meet them." To Abraham these appeared at first as men; but he entertained angels unawares, see Hebrews 13:2.
Related Commentaries of Genesis 18:2
Genesis 18:2
2 And he lift up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground,