Midrasch zu Bereschit 25:34

(Gen. 25:34:) SO ESAU DESPISED. < He was > of the opinion that he was joking with Jacob, but the Holy One gave his concurrence from above.¹⁸Gen. R. 63:14. It is so stated (in Exod. 4:22): THUS SAYS THE LORD: ISRAEL IS MY FIRST-BORN SON.

(Gen. 25:34:) SO ESAU DESPISED < HIS BIRTHRIGHT >. (Prov. 18:3:) WHEN A WICKED ONE COMES, THERE IS ALSO DESPISING. This refers to Esau, about whom it is stated: SO ESAU DESPISED. (Prov. 18:3, cont.:) {AND WHEN DISGRACE COMES}, [AND WITH DISGRACE, SHAME], since the famine came in his footsteps. Thus it is stated (immediately after the verse about Esau despising his birthright, in Gen. 26:1): NOW THERE WAS A FAMINE IN THE LAND.

“It was contemptible in his eyes to lay hands on Mordekhai alone, for they had told him of Mordekhai’s people; Haman sought to destroy all the Jews that were in the whole kingdom of Aḥashverosh, the people of Mordekhai” (Esther 3:6).
“It was contemptible [vayyivez] in his eyes to lay hands on Mordekhai alone” – contemptible one son of contemptible one. It is written there: “Esau showed contempt [vayyivez] to the birthright” (Genesis 25:34), and here it is written: “It was contemptible in his eyes.”
“Haman sought to destroy all the Jews” – Rabbi Shimon ben Yosei ben Lakonya said: In this world, Israel was likened to rocks, as it is stated: “For from the top of rocks I will see them” (Numbers 23:9); “look to the rock from which you were quarried” (Isaiah 51:1). They were likened to stones, as it is stated: “From the shepherd of the stone of Israel” (Genesis 49:24); “the stone that the builders rejected” (Psalms 118:22). The nations of the world were likened to pottery; that is what is written: “He will break it as a potter’s jug is broken” (Isaiah 30:14). If a boulder falls on a clay pot, woe to the pot; if the pot falls on a boulder, woe to the pot; one way or the other, woe to the pot. So it is regarding anyone who confronts them [the Jews]; he will receive his just deserts from them. And so it says in Nebuchadnezzar’s dream: “That a stone was hewn from the mountain, not with hands, and it crushed the iron, the bronze, the clay”¹⁰The stone will destroy the image made of the different materials, each representing an empire that will be destroyed. (Daniel 2:45).
Rabbi Ḥiyya bar Yannai said: If the royal purple is sold in the marketplace, woe to the buyer and woe to the seller. Likewise, Israel is the royal purple in which the Holy One blessed be He glories; that is what is written: “My servant Israel, that I glory in you” (Isaiah 49:3); if they are sold, woe to the seller and woe to the buyer.
To what is the wicked Haman comparable? To a bird that made a nest on the seashore and the sea swept away its nest, and it said: ‘I will not move from here until the sea becomes dry land and the dry land becomes sea.’ What did it do? It would take water from the sea in its mouth and pour it on the land, and would take dirt from the land and cast it into the sea. Its fellow came and stood alongside it and said to it: ‘Luckless and unfortunate one! Ultimately, what can you accomplish?’ So said the Holy One blessed be He to the wicked Haman: ‘World class fool! I said I would destroy them, so to speak, and could not, as it is stated: “He said He would destroy them, were it not for Moses, His chosen one, who stood before Him in the breach to turn back His wrath from destruction” (Psalms 106:23), and you said “to destroy, to kill, and to eliminate” (Esther 3:13) [them]. By your life, your head will be severed instead of their heads, as they are destined for deliverance and you for hanging.’

Rabbi said: Isaac circumcised Jacob, and Esau; and Esau despised the covenant of circumcision just as he despised the birthright, as it is said, "So Esau despised his birthright" (Gen. 25:34). Jacob clung to the covenant of circumcision, and circumcised his sons and his grandsons. Whence (do we know) that the sons of Jacob were circumcised? Because it is said, "Only on this condition will the men consent unto us to dwell with us… if every male among us be circumcised, as they are circumcised." (Gen. 34:22). Another text says, "Only on this condition will we consent unto you: if ye will be as we be" (Gen. 34:15). Hence thou canst learn that the sons of Jacob were circumcised. The sons of Jacob circumcised their sons and their grandsons. They gave it to them as an inheritance for an everlasting statute, until Pharaoh the Wicked arose and decreed harsh laws concerning them, and withheld from them the covenant of circumcision. And on the day when the children of Israel went forth from Egypt all the people were circumcised, both young and old, as it is said, "For all the people that came out were circumcised" (Josh. 5:5).