Midrash su Salmi 58:11

Another interpretation (of Numb. 31:2:) “Exact vengeance for the Children of Israel.” This text is related (to Job 36:7), “He does not withdraw His eyes from a righteous person […].” What is the meaning of “He does not withdraw His eyes from a righteous person (literally, withdraw from a righteous person his eyes)?” The Holy One, blessed be He, does not keep back from a righteous person what he wants to see with his eyes.¹³Numb. R. 22:5. [The text] teaches that Moses longed to see vengeance on the Midianites before he died, and [so] he requested from the Holy One, blessed be He, about it, that he should [see it] with his eyes. Thus it is stated concerning him (in Ps. 58:11), “A righteous person will rejoice when he sees vengeance, he will bathe his feet in the blood of the wicked person.” (Ibid.:) “A righteous person will rejoice,” this refers to Moses; “when he sees vengeance,” i.e., vengeance on Midian; “he will bathe his feet in the blood of the wicked person,” i.e., of Balaam. Moses said to Phinehas and the warring men, “I know that Balaam the Wicked is there, as he went to collect his wage. Before the wolf comes to the flock, spread the trap for him. And if you see that that wicked man is doing magic, show him the diadem, upon which it is written (according to Exod. 28:36), ‘holy to the Lord.’ And [when] he shall [then] fall, kill him.” (Numb. 31:8:) “And upon their [other] corpses they killed the kings of Midian,” as they were doing magic with Balaam and flying in the air; so they showed them the diadem and they fell upon their corpses. The sages said “It is written about Joshua (in Josh 1:5), ‘as I was with Moses, so I will be with you.’ So Joshua should have lived a hundred and twenty years like Moshe our teacher. And why were they shortened by ten years? Because at the time that the Holy One, blessed be He, said to Moses (in Numb. 31:2), ‘Exact vengeance for the Children of Israel…,’ even though the announcement of [his] death was [also] announced, he did not say, ‘Tomorrow I will die; what benefit is it to me to exact vengeance from Midian?’ Rather, he showed alacrity in the whole matter, as stated (in Numb. 31:6), ‘And Moses sent them.’ But Joshua did not do like this. When he came to war against thirty-one kings, he said, ‘If I kill them, I will die immediately, as happened to Moshe our teacher.’ What did he do? He began with one and stalled in the war [with the rest], as stated (in Josh. 11:18), ‘Joshua waged war with all those kings over a long period.’ [So] the Holy One, blessed be He, said to him, ‘See that I will shorten your years by ten years.’ David said (about this in Prov. 19:21), ‘Many thoughts are in the heart of a man, [but it is the counsel of the Lord that will stand].’”

Another interpretation (of Numb. 31:2:) EXACT VENGEANCE FOR THE CHILDREN OF ISRAEL. This text is related (to Job 36:7): HE DOES NOT WITHDRAW HIS EYES FROM A RIGHTEOUS PERSON. What is the meaning of HE DOES NOT WITHDRAW HIS EYES FROM A RIGHTEOUS PERSON (literally: WITHDRAW FROM A REGHTEOUS PERSON HIS EYES)? The Holy One does not keep back from a righteous person what he wants to see with his eyes.¹⁷Tanh., Numb. 9:4; Numb. R. 22:5. <The text> teaches that Moses longed to see vengeance on the Midianites before he died. Thus it is stated concerning him (in Ps. 58:11 [10]): A RIGHTEOUS PERSON WILL REJOICE WHEN HE SEES VENGEANCE. (Ibid.:) A RIGHTEOUS PERSON WILL REJOICE. This refers to Moses. (Ibid., cont.:) WHEN HE SEES VENGEANCE, i.e., vengeance on Midian. (Ibid., cont.:) HE WILL BATHE HIS FEET IN THE BLOOD OF THE WICKED PERSON, i.e., of Balaam.

Many miracles did the Holy One, blessed be He, do for Israel: He killed the firstborn of Egypt - that were compared to animals, as it is stated (Ezekiel 23: 20), "that their flesh is the flesh of donkeys;" He killed the firstborn of the captives; since they said to the captive that was imprisoned in the jail, "Do you want to go out and the Jews will [also] be delivered?" And he would say, "We will not ever leave from here in order that Israel not go out." That is why He judged them with [the Egyptians] - "from the firstborn of Pharaoh... to the firstborn of the captive." (Exodus 12:29) There is a parable about a king who made a joyous occasion for his son and killed his enemies. The king said, "Anyone who caused me joy should come to my son's joyous occasion, and anyone who is hated by me will be killed with the enemies." So [too], God made a joyous occasion for Israel, since He redeemed them - God said, "Anyone who loves My son should come and rejoice with My son." The proper ones of Egypt came and made a Pesach sacrifice with the Jews and went out with them, as it is stated (Exodus 12:38), "And also a mixed multitude went out with them." And all those that wanted Israel not to be redeemed died with the firstborn, as it is stated (Pslams 78:51), "And He smote all the firstborn of Egypt." They all cried out, as it is stated (Exodus 12:39), "and there was a great outcry in Egypt." They all came to kill Pharaoh. At that time, "And the Egyptians pressed upon the people (here read, as about the people)." (Exodus 12:33) And [the Jews at that time] were reciting Hallel; and Pharaoh announced to his warriors, "Come, let us call to Moshe and Aharon." God said to him, "You are releasing my children at night? You will not release my children at night, but rather they will go out [in plain sight,] in the middle of the day." The Jews dispersed into all of Egypt at that time, as it is stated (Ibid. 35), "And the children of Israel did according to the word of Moshe and borrowed from Egypt." And Moshe was busy with the bones of Yosef and the vessels of the Tabernacle that were prepared by Yakov, our father. And hence David said (Pslams 58:11), "The righteous one will rejoice, since he saw vengeance."