Midras Yesaya 1:27: Midrash Tanchuma, Devarim Rabbah, Ein Yaakov (Glick Edition) & Shemot Rabbah

Now these are the ordinances. The Holy One, blessed be He, said to Israel: If you fulfill the law and do not resort to (the courts) of the nations of the world, I will build you a Temple in which the Sanhedrin will convene, as it is said: And I will restore thy judges, as at first (Isa. 1:26). It is also written: Zion shall be redeemed with justice (ibid., v. 27), and Thus saith the Lord: Keep ye justice, and do righteousness; for My salvation is near to come (ibid. 56:1).

Another matter, “that the Lord your God will maintain for you the covenant and the kindness” (Deuteronomy 7:12) – Rabbi Shimon ben Ḥalafta said: To what is the matter comparable? To a king who married a noblewoman. She brought two gems into the marriage, and the king, too, provided for her two corresponding gems. The noblewoman lost hers, and the king, too, took his. Sometime later, she arose and applied herself, and she [found and] brought back her two gems. The king, too, brought his. The king said: ‘These and those shall be crafted into a crown and placed on the noblewoman’s head.’ So, you find that Abraham gave his descendants two gems, as it is stated: “For I love him, that he will command his children and his household after him, [and they will observe the way of the Lord, to perform righteousness and justice]” (Genesis 18:19).¹⁶The qualities of righteousness and justice are compared here to two gems. The Holy One blessed be He, too, provided them with two corresponding gems, kindness and mercy, as it is stated: “The Lord your God will maintain for you the covenant and the kindness,” and it says: “He will give you mercy, and He will be merciful to you, and He will multiply you…” (Deuteronomy 13:18). Israel lost theirs: “For you have transformed justice into hemlock and the fruit of righteousness into wormwood” (Amos 6:12). The Holy One blessed be He took His, as it is stated: “For I have withdrawn My peace…kindness and mercy” (Jeremiah 16:5). Israel arose and applied themselves, and brought back those two gems. From where is this derived? From that which is written: “Zion will be redeemed with justice and its penitents with righteousness” (Isaiah 1:27). The Holy One blessed be He, too, brought His. From where is this derived? From that which is written: “For the mountains will move and the hills will collapse, [but My kindness will not move from you and the covenant of My peace will not collapse, said the One who has mercy on you, the Lord]” (Isaiah 54:10). Once Israel brings theirs and the Holy One blessed be He gives His, the Holy One blessed be He says: ‘These and those will be crafted into a crown and will be placed on Israel’s head,’ as it is stated: “I will betroth you to Me forever; I will betroth you to Me with righteousness, with justice, with kindness and with mercy. I will betroth you to Me with faithfulness and you will know the Lord” (Hosea 2:21–22).

Ula said: "Jerusalem will not be redeemed except through charity," as it is said (Is. 1, 27) Zion shall be redeemed through justice, and her converts through Tzedakah (righteousness, or charity)." R. Papa said: "When the haughty shall cease to exist in Israel, then the magicians [among the Persians] shall cease, as it is said, (Ib. ib. 25) And purge away as with lye thy dross, and remove all thy tin. When the judges [of Israel] shall cease to be, the brutal executions of the Persian court-servants will cease, as it is said (Zeph. 3, 15) The Lord hath removed Mishpatecha (thy judges); He hath cleared away the enemy." R. Jochanan said: "When you see a generation in which wisdom decreases continually, you may hope for the Messiah, as it is said (II Sam. 22, 28) And the afflicted people thou wilt save." R. Jochanan said again: "If you see a generation in which chastisements and evils increase like the waters of the ocean increase, await the Messiah, as it is said (Isa. 59, 19) For there shall come distress like a stream." And thereafter is written, "But unto Zion shall come the redeemer." R. Jochanan said further: "Ben David will appear either in a generation in which all will be righteous, or in one in which all will be wicked. All righteous, as it is said, (Ib. 60, 21) And thy people — they all will be righteous, forever shall they possess the land. Or all wicked, as it is said (Ib. 59, 16) "And he saw that there was no man, and wondered that there was no intercessor." And it is also written (Ib. 48, 11) For My own sake, for My own sake, will I do it."