Midras Mazmur 45:3: Midrash Tanchuma, Aggadat Bereshit & Bereshit Rabbah

No man ever concentrated his mind and his heart upon his prayers as intensely as Abraham, our father, when he said to the Holy One, blessed be He: Far be it from Thee to do after this manner (Gen. 18:25). The Holy One, blessed be He, upon observing that Abraham pleaded for the sinners of Sodom, so that the world might not be destroyed, began to praise him, saying: Thou art fairer than the children of men; grace is poured on thy lips; therefore, God hath blessed thee forever (Ps. 45:3). Then Abraham asked, “Where am I fairer than the children of man? When I and my son enter a city, no one is capable of distinguishing between us.” (In those days) a man would live to be a hundred or two hundred years old without acquiring the distinguishing features of old age. “It is imperative, Master of the Universe, that You should distinguish between father and son, between old and young, so that the young may pay homage to the old.” The Holy One, blessed be He, replied: “Be assured I will begin to distinguish between young and old with you.” Abraham went to sleep, and when he arose in the morning he found that the hair of his head and beard had turned white. “Master of the Universe,” he exclaimed, “You have made me a public spectacle.” The Holy One, blessed be He, replied: Thy hoary head is a crown of glory (Prov. 16:31), and it says elsewhere: And the beauty of men is the hoary head (ibid. 20:29). Hence, it is said: Abraham was old.

Chapter 16: Torah [1] Now Abraham was ninety-nine years old (Genesis 17:1). It is said in Psalms (45:3), "Gird your sword upon your thigh, O mighty one, [in your splendor and your majesty]." The sons of Korah said this psalm about Abraham. "How fair you are among the sons of men," [meaning] more beautiful than the sons of Adam - [more beautiful] than Adam's descendants, Sheit, Enosh, and Kayin; [more beautiful] than the sons of Noach, [as it is written,] "And the Lord came down to see the city and the tower, which the sons of man had built" (Genesis 11:5). "Grace has been poured upon your lips" (Psalms 45:3). When you swore to the King of Sodom, as it is written, "I have lifted my hand to the Lord, God Most High" (Genesis 14:22), [the same grace that enabled you to become the anointed one] has been poured upon your lips. And for the reward that was given to you, therefore God has blessed you forever (Psalms 45:3), and all the praises that are sung of you, you have descended to the fiery furnace and been subjected to many trials, yet you stood firm and pursued after fifteen kings (Genesis 14:14-15) and were extolled throughout the world. Whatever you did, you did [well]. From here on out, I seek to make known my might, "Gird your sword upon your thigh, O mighty one." (Psalm 45:4) At that time, [God] glorified you and beautified you in the world. When was this? "Now Abraham was ninety-nine years old", and so on... "And I will establish My covenant with you", and so on... (Genesis 17:1-2).

R. Ze’era said: The laws of uncleanness apply to human beings: To men: When any man hath an issue out of his flesh (Lev. 15:2), and to women: If a woman have an issue (ibid., v. 19). This is the law: When a man dieth in a tent, everything shall be unclean (Num. 19:14). Thou art fairer than the children of men (Ps. 45:3). Moses is merely called human (but his essence is of a higher level). In what way? The Holy One, blessed be He, causes death and restores to life, He casts men into the pit and brings them out again, and Moses did likewise. He cast Korah and his followers, while still alive, into the pit, as it is said: So they, and all that appertained to them, went down alive into the pit (Num. 16:32). The Holy One, blessed be He, issued a decree, but he (Moses) caused it to be revoked, as is written: Therefore He said that He would destroy them, had not Moses His chosen stood before Him in the breach (Ps. 106:23). Grace is poured upon thy lips (ibid. 45:3) indicates that he spoke in their defense, as it is said: And Moses besought the Lord (Exod. 32:11), and He did not depart until the Lord repented (ibid., v. 14).