Midrasch zu Jeschijahu 63:16

(Gemara) Why Kashanim (like crimson)? It should be Kashani (like a crimson) R. Isaac said: "Thus said the Holy One, praised be He! unto Israel, 'If your sins were as many as the years that have been arranged and have come down from the six days of Creation until now, they shall nevertheless become white as snow. Raba expounded: "What is meant by the passage (Ib. ib. ib.) Go now, and let us reason together, will say the Lord, etc. Why, Go now; it should be Come now? Why, will say the Lord; it should be, Saith the Lord? This means that in the future, the Holy One, praised be He! will say unto Israel, 'Go to your ancestors, they shall rebuke you.' And Israel will say: 'Sovereign of the universe, to whom shall we go? Shall we go to Abraham to whom thou hast said (Gen. 15, 13.) Know of a surety that thy seeds shall he stranger, etc., and he did not pray for us? Shall we go to Isaac who when blessing Esau said, (Ib. 27, 40.) And it shall come to pass, that when thou shalt have the dominion, etc., and he also did not pray for us? Shall we go unto Jacob, to whom Thou didst say (Ib. 46, 4.) I will go down with thee unto Egypt, and even he did not pray for us? Let then the Lord say, to whom shall we now go?' Then will the Holy One, praised be He! say to them, 'Because ye have attached yourselves to me, therefore if your sins be even as crimson, they shall become as white as snow.'" R. Samuel b. Nachmeini said: "What is meant by the passage (Is. 63, 16.) For Thou art our father; for Abraham, knoweth nothing of us, and Israel recognizeth us not; Thou, O Lord, art our Father, our Redeemer, etc., i. e., In the future, the Holy One, praised be He! will say to Abraham, 'Thy children have sinned before me,' and Abraham will answer, 'Sovereign of the universe, let them be wiped off for the sake of Thy holy name.' 'I shall tell this to Jacob, who had trouble raising his own children,' said the Lord, 'perhaps he will pray for mercy upon them.' The Lord then said unto Jacob, 'Thy children have sinned'; whereupon Jacob also replied, 'Sovereign of the universe! Let them be wiped off for the sake of Thy holy name.' Then said the Lord, 'Neither sense can be found with the aged, nor wise counsel with the young.' The Lord then said unto Isaac, 'Thy children have sinned.' Whereupon Isaac said unto Him, 'Sovereign of the universe, 'Are they my children and not Thine? When they answered Thee, We will do and listen. Thou didst call them (Ex. 4, 22.) My first-born son, and now are they mine and not Thine? Furthermore, how long a time have they sinned before Thee? Let us see; the duration of a man's life is about seventy years. Take off twenty years that Thou dost not punish and there will remain but fifty years. Take off the nights and only twenty-five will remain. Deduct twelve and one-half years spent in praying, eating and in performing other necessities and only twelve and one-half years will remain. Now if Thou wilt bear the whole burden, it is well, but if not, let me bear one-half [of the burden], and Thou the other half. And if Thou wilt say that I must bear the whole, behold! I was ready to sacrifice myself for Thee!' Immediately the children of Israel will begin to say [unto Isaac], 'For thou alone art our father.' Isaac will then say unto them, 'Instead of praising me, praise ye the Holy One, praised be He!' Whereupon they will lift up their eyes unto the Holy One, praised be He! and will say, 'Thou, O Lord, art our Father, our Redeemer (Is. 63, 16)." R. Chiya b. Abba, in the name of R. Jochanan, said: "Jacob (our father) was destined to go down to Egypt in iron chains, but his merits saved him [from such a fate], as it is written (Hosh. 11, 4.) With human cords I ever draw them forward, with leading strings of love: and I was to them as those that lift off the yoke from their jaws, and I held food unto them."

“My beloved is mine, and I am his, who herds among the lilies” (Song of Songs 2:16).
“My beloved is mine, and I am his,” He is God for me, and I am a nation for Him. He is God for me, “I am the Lord your God” (Exodus 20:2). I am a people and a nation for Him, as it is stated: “Pay attention to Me, My people, and listen to Me, My nation” (Isaiah 51:4). He is a father to me, and I am a son to Him. He is a father to me, “For You are our Father” (Isaiah 63:16). I am a son to Him, “My son, My firstborn, Israel” (Exodus 4:22). He is a shepherd to me, “Shepherd of Israel, listen” (Psalms 80:2). I am His flock, “you, My flock, flock of My pasture” (Ezekiel 34:31). He is my guardian, “Behold, the Guardian of Israel does not slumber and does not sleep” (Psalms 121:4). I am His vineyard, as it is stated: “For the house of Israel is the vineyard of the Lord of hosts” (Isaiah 5:7).
He is for me against those who provoke me, and I am for Him against those who anger Him. He is for me against those who provoke me, as He smote the firstborn of Egypt, as it is stated: “I will pass in the land of Egypt” (Exodus 12:12); “it was at midnight and the Lord smote every firstborn” (Exodus 12:29). I am for Him against those who anger Him, as I slaughtered the gods of Egypt, and likewise, “against all the gods of Egypt I will administer punishment” (Exodus 12:12), and I slaughtered them to Him, as it is stated: “Behold, will we slaughter the abomination of Egypt before their eyes, and they will not stone us?” (Exodus 8:22). Likewise, “they shall each take for them a lamb for each patrilineal home” (Exodus 12:3).
He said to me: ‘Let the proportion [hamazeg] not be skewed,’ as it is stated: “Your navel is a moon-shaped goblet, may it not lack mixed wine [hamazeg]” (Song of Songs 7:3). I said to Him: ‘You are my good beloved, if only Your goodness will never be lacking from me,’ just as it says: “The Lord is my Shepherd, I will not lack” (Psalms 23:1).
Rabbi Yehuda bar Rabbi Ilai said: He sang to me and I sang to Him; He lauded me and I lauded Him. He called me: “My sister, My love, My faultless dove” (Song of Songs 5:2), and I said to Him: “This is my beloved and this is my companion” (Song of Songs 5:16). He said to me: “Behold you are fair my love” (Song of Songs 4:1), and I said to Him: “Behold, you are fair, my beloved, pleasant too” (Song of Songs 1:16). He said to me: “Happy are you Israel, who is like you?” (Deuteronomy 33:29). I said to Him: “Who is like You among the powers, Lord?” (Exodus 15:11). He said to me: “Who is like Your people Israel, one nation in the land” (I Chronicles 17:21). I declare the unity of His name twice daily: “Hear Israel, the Lord is our God, the Lord is one” (Deuteronomy 6:4). When I require something, I seek it only from His hand, as it is stated: “It was during those many days, that the king of Egypt died; [the children of Israel sighed due to the bondage, and they cried out, and their plea rose to God due to the bondage.] God heard their groaning…God saw the children of Israel” (Exodus 2:23–25). When He requires something, he seeks it only from me and from my hand, as it is stated: “Speak to the entire congregation of Israel, saying: [In the tenth day of this month they shall take for themselves every man a lamb]” (Exodus 12:3). When I require something, I seek it only from His hand, as it is stated: “Pharaoh approached and the children of Israel raised [their eyes and…the Egyptians were traveling after them… the children of Israel cried out to the Lord]” (Exodus 14:10). When He requires something, He seeks it only from me, as it is stated: “Speak to the children of Israel and let them take a gift for Me” (Exodus 25:2). When I had trouble, I sought [salvation] only from Him: “The Children of Israel cried out to the Lord, as he had nine hundred iron chariots, and he oppressed the Children of Israel forcefully…” (Judges 4:3). What is forcefully? It was with cursing and blaspheming. When He required something, He sought it only from me, as it is stated: “They shall make a sanctuary for Me” (Exodus 25:8).