Midras 2 Raja-raja 2:19: Ein Yaakov (Glick Edition), Shemot Rabbah & Bereshit Rabbah

(Ib., ib., ib.) And tore of them forty and two boys. Said R. Jose, the son of R. Chanina: "On account of the forty-two sacrifices that Ballak, the king of Moab. offered, it happened that forty-two Israelites' children were torn." Is this the real cause? Behold R. Juda said in the name of Rab: "Always shall a man occupy himself with the study of the Torah, and the fulfillment of meritorious deeds, even it is not for its real purpose, because out of a selfish purpose he will come to do so for its real purpose, for as reward for the forty-two sacrifices that Ballak, the king of Moab offered, he was rewarded that Ruth came forth from him of whom Solomon is a descendant, concerning whom the passage says (I Kings 3, 4) One thousand burnt-offerings did Solomon offer upon the altar, and R. Jose, son of R. Chanina said: "Ruth was the daughter of King Eglon, who was the grandson of Ballak, the king of Moab." [Hence I see that at the end he meant well]. However, since his real purpose was to curse Israel, thus through the above incident his curse was fulfilled. (II Kings 2, 19) And the men of the city said unto Elisha, 'Behold, we pray thee; the situation of this city is pleasant, as my Lord seeth; but the water is bad, and the land causes miscarriages.' Since the water is bad and the land causes miscarriages why do they say that the city is splendid? Said R. Chanin: "It is the usual esteem in which inhabitants hold their place."

Another matter, “Betzalel crafted” – that is what is written: “I will bring a remedy for you” (Jeremiah 30:17). The attributes of the Holy One blessed be He are not like the attributes of flesh and blood. The attribute of flesh and blood is to wound with a chisel and heal with a bandage. But the Holy One blessed be He heals with that with which He wounds, as it is stated: “They arrived in Mara and were unable to drink water from Mara” (Exodus 15:23). Why? “Because it was bitter [marim]” (Exodus 15:23). Rabbi Levi said: That generation was bitter in its actions. “He cried out to the Lord and the Lord showed him a tree” (Exodus 15:25). What was it? Some say it was an olive tree, some say it was a willow, some say it was oleander, and some say it was the roots of fig trees and the roots of pomegranate trees.²All of these materials are bitter. He took it and cast it into the water. Immediately, the water sweetened. That is, “and from your wounds I will heal you” (Jeremiah 30:17).
Likewise you find with the water of Elisha, what is written? “The water is bad and the land causes bereavement” (II Kings 2:19). He said to them: “Bring me a new flask and place salt in it, and they brought it to him” (II Kings 2:20). What is written? “The water was cured to this day, in accordance with the word of Elisha that he spoke” (II Kings 2:22).
Likewise you find regarding Israel; he rebuked them with [the word] ‘therefore,’ as it is stated: “Therefore, prostitute, hear the word of the Lord” (Ezekiel 16:35), and with [the word] ‘therefore’ He is destined to restore them. as it is stated: “Therefore, behold, I will seduce her” (Hosea 2:16), and one seduces only a virgin. As it is stated: “If a man seduces a virgin” (Exodus 22:15).³Thus, although Israel is compared to a prostitute by Ezekiel, eventually they are compared to a virgin, who has not experienced sin. So, too, Israel sinned in Shittim. As it is stated: “Israel were residing in Shittim [and the people began to engage in licentiousness]” (Numbers 25:1), and they were healed with shittim, as it is stated: “Betzalel crafted the Ark of acacia wood [atzei shittim].”

“Jacob remained alone, and a man wrestled with him until the break of dawn” (Genesis 32:25).
“Jacob remained alone, and a man wrestled with him.” “Yeshurun, there is none like God, Who rides the heavens in your assistance” (Deuteronomy 33:26). Rabbi Berekhya said in the name of Rabbi Yehuda ben Rabbi Simon: “There is none like God,” but who is like God? It is Yeshurun,¹The Jewish nation. the best and most praiseworthy among you. You find that everything that the Holy One blessed be He is destined to perform in the future, He had them performed earlier, by means of the righteous in this world. The Holy One blessed be He revives the dead and Elijah revives the dead.²I Kings 17:22. The Holy One blessed be He withholds rain and Elijah withholds rain.³I Kings 17:1. The Holy One blessed be He blesses the scarce and Elijah blesses the scarce.⁴I Kings 17:14–16. The Holy One blessed be He revives the dead and Elisha revives the dead.⁵II Kings 4:33–35. The Holy One blessed be He remembers the barren and Elisha remembers the barren.⁶II Kings 4:16. The Holy One blessed be He blesses the scarce [to increase it] and Elisha blesses the scarce [to increase it].⁷II Kings 4:2–7. The Holy One blessed be He sweetens the bitter and Elisha sweetens the bitter.⁸II Kings 2:19–22. The Holy One blessed be He sweetens the bitter with bitter⁹Shemot Rabba 23:3. and Elisha sweetened the bitter with bitter.
Rabbi Berekhya said in the name of Rabbi Simon: “There is none like God,” but who is like God? It is Yeshurun, Israel the elder. Just as the Holy One blessed be He, it is written in His regard: “The Lord alone will be exalted [on that day]” (Isaiah 2:17), Jacob, too: “Jacob remained alone.”