מדרש אויף בראשית 18:2

Normally, if a student is ailing, and his master plans to visit him, his fellow students precede the master to their colleague’s home in order to inform him of the visitor who will be coming. The Holy One, blessed be He, did not do so. After Abraham was circumcised, and while he was still suffering the effects of the circumcision, He told the angels: Go, visit him! However, before they departed, the Holy One had preceded them. Thus, it is said: And the Lord appeared unto him (Gen. 18:1), and this is followed by the verse: And he lifted up his eyes and looked, and lo, three men stood over against him (ibid., v. 2). Is there any condescension greater than this?

Another interpretation (of Cant. 4:6): UNTIL THE DAY BECOMES COOL. Until the kingdom of the Holy One appears in this world. (Ibid., cont.:) AND THE SHADOWS FLEE, i.e., the shadows of the kingdom. (Ibid., cont.:) I WILL GO UNTO THE MOUNTAIN OF MYRRH, i.e., Jerusalem. Thus it is stated (in Cant. 5:1): WHEN I COME TO MY GARDEN, MY SISTER, MY BRIDE, I HAVE PLUCKED MY MYRRH ALONG WITH MY SPICE. (Josh. 5:3:) UNTO THE MOUND OF FORESKINS,²⁰Buber again suggests emending to fit Cant. 4:6: UNTO THE MOUND OF FRANKINCENSE. since he took the foreskins and made a mound of them. For that reason the Holy One was revealed to him, as stated (in Gen. 18:1): THEN < THE LORD > APPEARED UNTO HIM. Now when the angels saw this, they also came along with the Holy One, as stated (in Gen. 18:2): WHEN HE LIFTED HIS EYES AND LOOKED, BEHOLD, THERE WERE THREE MEN < STANDING NEAR HIM >. And so David gives praise (in Ps. 25:10): ALL THE PATHS OF THE LORD ARE STEADFAST LOVE AND TRUTH. What is the meaning of ALL THE PATHS OF THE LORD ARE STEADFAST LOVE AND TRUTH? < With reference to > the Torah, its beginning is steadfast love,²¹See above, 4:1; below, 5:2. its end is steadfast love, and its middle is steadfast love. Its beginning is steadfast love. Where is it shown? You find that when the Holy One formed Eve, he adorned her and brought her to Adam, as stated (in Gen. 2:22): THEN THE LORD GOD BUILT THE RIB < WHICH HE HAD TAKEN FROM THE HUMAN INTO A WOMAN >. What is the meaning of BUILT? R. Abbahu said: In Arabia they call the plaited coiffure a "building."²²Cf. Ber. 61a; Shab. 95a; ‘Eruv. 18a; Nid. 45b; ARN, A, 4; Gen. R. 18:1; M. Pss. 25:11; above 4:1; below 5:2. Its end is steadfast love, < i.e., > at Moses' death when the Holy One attended him in his glory,²³BKBWDW: perhaps a misprint for BKBWRW, “at his burial.” as stated (in Deut. 34:6): AND HE BURIED HIM IN THE VALLEY. At the middle there is steadfast love in the case of Abraham, as stated (in Gen. 17:2): AND LET ME PUT MY COVENANT BETWEEN ME AND YOU. When the Holy One was revealed to him, he was sitting, as stated (in Gen. 18:1): < THEN THE LORD APPEARED UNTO HIM > … AS HE WAS SITTING AT THE TENT DOOR IN THE HEAT OF THE DAY.²⁴Below, 8:28. Abraham went to stand up. The Holy One said to him: Do not trouble yourself to stand up. Sit down! It is so stated (in Ps. 110:1): THE LORD (God) SAID TO MY LORD (Abraham): SIT DOWN AT MY RIGHT HAND. Abraham said to him: Is this good manners for me to be sitting while you are standing? The Holy One said to him: Do not trouble yourself. You are an old man of a hundred years. Sit down! The Holy One said to him: By your life, because you are sitting while I stand, your children at the age of three years, at the age of four years, are going to be sitting in the academies and in the synagogues with me standing over them. Thus it is stated (in Ps. 82:1): GOD STANDS IN THE DIVINE CONGREGATION. Abraham began to praise²⁵Rt.: QLS, possibly related to the Gk.: kalos, which means “beautifully.” God (according to Ps. 18:36 [35]): YOU ALSO GAVE ME THE SHIELD OF YOUR SALVATION, when the kings had pursued < me >. It is so stated (in Gen. 15:1): FEAR NOT, ABRAM, I AM YOUR SHIELD. (Ps. 18:36 [35], cont.:) YOUR RIGHT HAND SUSTAINED ME, when you grasped the foreskin along with me as I was cutting. (Ibid., cont.:) AND YOUR CONDESCENSION MAGNIFIED ME, in that I was sitting while you were standing.

R. Judah bar Shallum the Levite said: The students proceed < first > and after that, the master; but the Holy One does not act so. Rather, for the sake of Abraham, who was sitting in pain (due to his recent circumcision in Gen. 17:26), the Holy One said to his angels: Let us go and visit Abraham. While they were proceeding, < first > God appeared to him and after that, the angels. It is so stated (in Gen. 18:1): THEN THE LORD APPEARED UNTO HIM BY THE TEREBINTHS OF MAMRE, and after that (in vs. 2): RAISING HIS EYES, HE LOOKED; < AND HERE WERE THREE MEN >…. Ergo (in Ps. 18:36 = II Sam. 22:36): AND YOUR HUMILITY HAS MAGNIFIED ME.