Midrash su Gioele 4:21

(Fol. 23) R. Jochanan said: "Every acacia tree which the nations have taken from Jerusalem, the Lord will cause to be restored to her; as it is said (Is. 41, 19) I will place in the wilderness the cedar, the acacia and the myrtle, and the oil tree, etc. Wilderness refers to Jerusalem; as it is said (Ib. 64, 9) Zion is become a wilderness, Jerusalem, a desolate place." Another thing said R. Jochanan: "Whoever studies the Torah but does not teach it to others is likened unto a myrtle in the desert, from which no one enjoys any benefit." Others contend that R. Jochanan said: "Whoever studies the Torah, and teaches it in a place where there is no other scholar, is likened unto a myrtle in the desert, which is very precious." Another thing said R. Jochanan: "Woe to the Romans, for whom there will be no remedy; as it is said (Ib. 60, 17) Instead of the copper will I bring gold, and instead of the iron will I bring silver, and instead of wood, iron. But what can they bring for R. Akiba and his associates, who were executed by the Romans? Concerning them it is said (Joel 4, 21) I will avenge, [but for] their blood I shall not avenge, fur the Lord dwelleth in Zion."

And the Lord went before them by day (Exod. 13:21). Has it not already been said: Do not I fill heaven and earth? (Jer. 23:25), and also: The earth is full of His glory (Isa. 6:3)? Why, then, does Scripture say: And the Lord went before them? In order to reveal to the nations of the world the extent of His love for Israel, so that they would pay homage to them. However, not only did they not pay homage to them, but they slaughtered them most cruelly. Because of that it says: I will gather all the nations, and will bring them down to the valley of Jehoshaphat; and I will enter into judgment with them there for My people and for My heritage Israel, whom they scattered among the nations (Joel 4:2). It does not say “Because they committed idolatry” or “committed sexual crimes” or (were guilty) “of shedding blood,” but rather: For My people and for My heritage Israel whom they have scattered among the nations. And it says also: Egypt shall be a desolation, and Edom shall be a desolate wilderness (ibid., v. 19), while at that very time Judah shall be inhabited forever, and Jerusalem from generation to generation. And I will hold as innocent their blood that I have not held as innocent (ibid., v. 20). When will that be? When the Lord dwelleth in Zion (ibid.).