Midrash sur Rois 2 24:9

“The elders of the daughter of Zion sit on the ground, are silent. They have placed dust on their heads, have girded themselves with sackcloth. The virgins of Jerusalem have lowered their heads to the ground” (Lamentations 2:10).
“The elders of the daughter of Zion sit on the ground, are silent.” Rabbi Elazar said: Let the portion of vows not be insignificant in your eyes, as it is on account of the portion of vows that the Great Sanhedrin of Zedekiah were killed. When Yekhonya was exiled, King Nebuchadnezzar appointed him¹⁰⁶Zedekiah. over five kings. That is what is written: “Send to the king of Edom, to the king of Moav, to the king of the children of Ammon, to the king of Tyre and to the king of Sidon, in the hand of the messengers who come to Jerusalem to Zedekiah, king of Judah” (Jeremiah 27:3). He would enter and exit before him without permission.¹⁰⁷Zedekiah had unfettered access to Nebuchadnezzar. One day, he entered before him and saw that he was ripping the flesh of a hare and eating it raw. [Nebuchadnezzar] said to him: ‘Take an oath to me that you will not publicize this about me,’ and he took an oath to him. On what did he administer the oath to [Zedekiah]? Rabbi Yosei ben Rabbi Ḥanina said: On the inner altar. The five kings were sitting and maligning Nebuchadnezzar before Zedekiah and saying to him: ‘The kingdom is not suitable for Nebuchadnezzar, but rather it is suitable for you, as you are from the offspring of David.’ He, too, maligned Nebuchadnezzar and said: ‘I saw that he was ripping the flesh of a hare and eating it.’ Immediately, they sent [a message] to the king, saying: ‘This Jew who enters and exits before you without permission said about you: I saw that Nebuchadnezzar was ripping the flesh of a hare and eating it.’ That is what is written: “Zedekiah rebelled against the king of Babylon” (II Kings 24:20).
Immediately, he¹⁰⁸Nebuchadnezzar. came and settled in Daphne of Antioch and the Great Sanhedrin went to greet him. When he saw that they were all men of noble form, he issued a command and had seats of honor brought for them, and he seated them. He said to them: ‘Teach me the Torah.’ Immediately they began reading each and every portion and translating it before him. When they reached the portion of vows: “A man who takes a vow” (Numbers 30:3), he said to them: ‘If he wishes to renege on it, can he or can he not do so?’ They said to him: ‘He can go to a Sage and [the Sage] can nullify his vow for him.’ He said to them: ‘It seems to me that you nullified for Zedekiah the oath that he took to me.’ Immediately, he decreed and had them placed down on the ground. That is what is written: “The elders of the daughter of Zion sit on the ground, are silent.” “They have placed dust [on their heads],” they began mentioning the merit of Abraham, as it is written: “I am dust and ashes” (Genesis 18:27). “Have girded themselves with sackcloth,” they began mentioning the merit of Jacob, as it is written: “He placed sackcloth on his loins” (Genesis 37:34).¹⁰⁹The Sages began to pray to God for mercy in the merit of Abraham and Jacob, both of whom took oaths and were careful to fulfill them (Etz Yosef; see Genesis 14:22, 28:20). What did they do to them? They tied their hair to horses’ tails and had them run from Jerusalem to Lod. That is what is written: “The virgins of Jerusalem have lowered their heads to the ground.”¹¹⁰They did so in mourning for the Sages. Alternatively, the Sages are alluded to with the term virgins because of their purity.

Therefore the Holy One, blessed be He, established two yeshivot (at Sura and Pumbeditha) for the Israelites where they studied the Torah day and night, and where they assembled from all parts of the world twice each year, in the months of Adar and Elul. They came together to “battle” the problems encountered in the Torah until they had resolved them and reached a definitive decision concerning them. They would adduce arguments from the Torah, the Mishnah, and the Talmud so that the Israelites might not sin against the law, as it is said: Great peace have they that love Thy law; and there is no sinning for them (Ps. 119:165). Scripture informs us: The Lord will give strength unto His people, the Lord will bless His people with peace (Ps. 29:11). Hence, these two yeshivot experienced neither captivity, persecution, nor pillage; and neither Greece nor Rome ever conquered them.⁶The author of this statement apparently believed that the academies in Babylon were established prior to Alexander the Great’s conquest of the Middle East and following the exile in the reign of Nebuchadnezzar. The Holy One, blessed be He, led the people out of Jerusalem with their Written and Oral Law twelve years before its destruction, as it is written: And he carried away all Jerusalem, and all the princes and all the mighty men of valor, even ten thousand captives, and all the craftsmen and smiths; none remained save the poorest sort of people of the land (II Kings 24:14). Is there might among men being led into exile? These were the mighty ones in their knowledge of Torah, as is indicated in the verse: In the Book of the Wars of the Lord (Num. 21:14).

Juda and Hezekiah, the sons of R. Chiya, were sitting at a banquet before Rabbi [the Nassi] and did not utter a word. The Rabbis remarked: "Let the wine get the better of the youngsters (let them become a little merry), so that they shall say something." As soon as they were filled with wine they began sayiug: "Ben David will not come until there will be an end to the two families (dynasties), that of the Babylonian Exilarchs and that of the Princes of Palestine, as it is said (Is. 8, 14) And he will be for a sanctuary; but also for a stone of stumbling, and for a rock to fall over unto the two houses of Israel." Whereupon Rabbi exclaimed: "Children! you are throwing thorns in my eyes!" "Rabbi," remarked they "Yayin (wine) amounts numerically to seventy, and the word Sod (secret) amounts to seventy, hence as soon as wine enters the secret goes out." R. Chisda lectured: "What is the meaning of the passage (Dan. 9, 14) Therefore was the Lord hurried to bring the evil, and He brought it upon us; for the Lord our God is righteous; i.e., is it because the Lord our God is righteous that He hurried to bring upon us the evil? No, this means, the Holy One, praised be He! did charity with Israel in that He caused the exile of Zedekiah to come while those of the exiled of Yechanyah were still alive; as it is said concerning Yechanyah (II Kings 24, 16) And the craftsmen and the locksmiths a thousand; i.e., Cheresh means if they opened a question all became deaf, and Massger (locker) if they closed the argument of a thing none could reopen it." And how many were they? A thousand. Ulla said: "The charity consists in that the Holy One, praised be He! made the exile earlier by two years indicated through the word V'noshantem." R. Acha b. Jacob said: "Infer from this that 'quick' means eight hundred and fifty-two years to the Omnipotent."