Midrash su Isaia 60:22

“My eye will flow and will not cease, without respite. Until the Lord looks out and sees from Heaven” (Lamentations 3:49–50).
“My eye will flow and will not cease.… until the Lord looks out and sees from Heaven” – Rabbi Aḥa said in the name of Rabbi Shmuel bar Naḥman: In three places we found the Divine Presence connected with the redemption. What is the source? “A stomping ground for wild donkeys, a pasture of flocks” (Isaiah 32:14).⁷⁶This is a reference to the Temple after its destruction. What is written thereafter? “Until a spirit will be poured upon us from on high and wilderness will become fertile land and fertile land will be considered as forest” (Isaiah 32:15). Similarly, “The smallest will become a thousand, and the youngest [a mighty nation; I am the Lord, at its time, I will hasten it]” (Isaiah 60:22), and it is written thereafter: “The spirit of the Lord God is upon me, because the Lord has anointed me” (Isaiah 61:1). And this, “My eye will flow,” and it is written thereafter: “Until the Lord looks out and sees from Heaven.”
“My eye distressed my soul over all the daughters of my city” (Lamentations 3:51).
“My eye distressed my soul” – Rabban Shimon ben Gamliel said: There were five hundred primary schools in Beitar, and the smallest among them had no fewer than three hundred children. They would say: If our enemies come against us, we will emerge and stab them with these quills. When the iniquities were the cause and the enemies came, they wrapped each and every one of them in his scroll and they burned them, and I am the only one of them who survived. I applied to myself the verse: “My eye distressed my soul over all the daughters of my city.”

“Just as you do not know the path of the wind, or how the bones grow in the womb of one who is pregnant; so you will not know the work of God, who does everything” (Ecclesiastes 11:5).
“Just as you do not know” – there are seven matters obscured from people, and they are the day of death, the day of consolation, the profundity of judgment, how one profits, what is in the heart of another, what is in a woman’s pregnancy, and this kingdom of Edom, when it will fall. The day of death, from where is it derived? It is as it is stated: “Man [also] does not know his time” (Ecclesiastes 9:12). The day of consolation, from where is it derived? It is as it is stated: “I am the Lord; at its time I will hasten it” (Isaiah 60:22). The profundity of judgment, from where is it derived? It is as it is stated: “For judgment is God’s” (Deuteronomy 1:17). How one profits, from where is it derived? It is as it is stated: “This is the gift of God” (Ecclesiastes 5:18). What is in the heart of another, from where is it derived? It is as it is stated: “I am the Lord, who probes the heart” (Jeremiah 17:10). What is in a woman’s pregnancy, from where is it derived? It is as it is stated: “Or how the bones grow in the womb of one who is pregnant.” And this kingdom of Edom, when it will fall, from where is it derived? It is as it is stated: “For it is a day of vengeance in My heart” (Isaiah 63:4).

Another comment on why she was called Keturah: Her deeds were as pleasant as the fragrance of incense (ketar). And she bore him Zimran, and Jokshan, and Medan, etc. (ibid. 25:2). Therefore Scripture says: Though thy beginning was small, yet thy end shall greatly increase (Job 8:7). The Holy One, blessed be He, proclaimed: The righteous beget good and wicked sons in this world, but in the world-to-come all of them shall be righteous and shall inherit the land forever (Isa. 60:2). And it says also: The smallest shall become a thousand, and the least a mighty nation; I, the Lord, will hasten it in its time (ibid., v. 22). And so may it be.