Midrasz do Diwrej ha-jamim II 24:25

Others say: Let Amalek, the ingrate, come and exact payment of the ingrate people (Israel). Similarly, (II Chronicles 24:26) "And these are the men who rebelled against him (Yoash), etc.": Let these ingrates come and exact payment of the ingrate Yoash, viz. (Ibid. 22) "and King Yoash did not remember the lovingkindness that (Zechariah's) father Yehoyada had done for him, and he killed his son. As he was dying, he said: "May G d see this and demand redress." What was his punishment? (Ibid. 23) "And it happened at the turn of the year that the army of Aram attacked (Yoash) …and the L rd delivered into their hands a great host." Why? (Ibid. 24) "for they had forsaken the L rd, the G d of their fathers. And with Yoav they effected shefatim." Do not read it "shefatim" (judgment), but "shoftim" (judges). How so? They appointed over him cruel guards, who had never known a woman in their lives and who tortured him with sodomy, as it is written (Hoshea 5:5) "And the pride of Israel (Yoash) will be tortured, etc." (II Chronicles 24:25) "and when they left him (Yoash) — for they left him with many wounds — his servants rebelled against him because of the blood of the sons of Yehoyada the Cohein, and they killed him on his bed and he died."

Rabbi Yehoshua from Sichnin in the name of Rabbi Levi said: It is written 'The wicked have drawn out the sword [and have bent their bow; to cast down the poor and needy, to slay such as are upright in the way] (Ps. 37:14) - 'The wicked have drawn out the sword and have bent their bow' this is Kayin; 'to cast down the poor and needy, to slay such as are upright in the way' this is Hevel. 'Their sword shall enter into their own heart, and their bows shall be broken. ' (Ps. 37:15). "You shall become a ceaseless wanderer on earth" (Gen. 4:9) "and God said to Kayin, where is Hevel your brother"(Gen. 4:12) - a parable: a governor was walking in the middle of the square, he encountered a murdered body and someone over it, and asked 'who killed him?' And the other responded: 'I ask you the same thing.' And the governor answered: you didn't answer. A parable: one entered in a orchard and collected strawberries and ate, and the owner of the garden run after him, and asked: 'what do you have in your hands?' he answered: 'nothing!', the owner says: 'look at your dirty hands!' So too, Kayin answered the Holy One of Blessing: 'Am I my brother's keeper?' (Gen. 4:9) "The voice of the bloods of your brother scream etc." (Gen. 4:10) - Rabbi Yudan and Rabbi Huna and the rabbis [comment]. Rabbi Yudan says: It is not written 'the blood of your brother', but 'the bloods of your brother', [this teaches] his blood and the blood of his descendants. Rabbi Huna said: "Surely I have seen yesterday the bloods of Navot, and the bloods of his sons, says Ad-nai" (II Kings 9:26) - it is not written 'the blood of Navot and the blood of his sons', but the bloods of Navot and the bloods of his sons - his blood and the blood of his descendants. The rabbis say 'and he died..' 'the blood of Yehoyada' is not written, rather, 'the bloods of Yehoyada' (II Chron. 24:25) - his bloods and the bloods of his descendants. Said rabbi Shime'on Bar Yochai: It is hard to say this thing, and the mouth cannot explain it completely, [it is similar] to two athletes that are wrestling before the king, if the king wanted to [he could] separate them, but the king did not want to separate them, one overwhelmed the other and killed him, so 'the voice of the bloods of your brother scream to Me from the land'. She (the voice of Hevel’s blood) could not go up above/lema'lah, for as yet no soul/neshamah had gone up to there; and below/lematah she could not stand, for no human had been buried there yet, and [so] his blood was cast upon the trees and the stones.

R. Judah the Prince stated: Amalek had to travel through the land of five nations to wage war against Israel at Rephidim, as it is said: Amalek dwelleth in the land of the south; and the Hittite, and the Jebusite, and the Amorite, dwell in the mountains; and the Canaanite dwelleth by the sea, and along by the side of the Jordan (Num. 13:29). From this verse you learn that Amalek dwelt farther away than (the others). R. Nathan stated: Amalek came from the mountains of Seir and traveled nearly four hundred parasangs to Rephidim to wage war against Israel. Others say: He allowed the ungrateful Amalek to come and exact retribution from an ungrateful people. Thus it says: And these are they that conspired against him: Zabad the son of Shemeath the Ammonitess (II Chron. 24:26). He let these ungrateful ones come and exact retribution from the ungrateful Joash, as it is said: Thus Joash the king remembered not the kindness which Jehoiada, his father, had done to him, but slew his son. And when he died, he said: “The Lord look upon it, and require it” (ibid., v. 22). What was his punishment? And it came to pass, when the year was come about, that the army of the Arameans came up against him. And they came to Judah and Jerusalem, and destroyed all the princes of the people from among the people…. so they executed judgment upon Joash (ibid., v. 23–24). Do not read the word as shefatim (“judgment”) but as shiputim (“sport”). They stationed cruel guards over him who had not had sexual relations with women, and they tortured him with acts of sodomy, as is said: And tortured but the pride of Israel (Hos. 5:5). It is written also: And when they were departed from him—for they left him in great diseases—his own servants conspired against him for the blood of the sons of Jehoiada the priest, and slew him on his bed, and he died; and they buried him in the city of David, but they buried him not in the sepulchers of the kings (II Chron. 24:25).