-Sanhedrin.97a.2
What were these twelve months for? From the [new collection] they would offer the continual sacrifices and the additional sacrifices, the libations, the omer, the two loaves, and the showbread, all the communal offerings, and the guards of the towers of Edar [Migdal Eder] and the guards of the city.
-Mishnah Shekalim 7:4
And Jacob proceeded and pitched his tent beyond Migdal Eder, the place where the King Messiah will reveal Himself at the end of days.
-Targum Jonathan on Genesis 35:21
If Israel repents for even a single day, the Son of David (Messiah) will come immediately. If they do not repent, the redemption will come in its appointed time.
-Sanhedrin 97b
The school of Eliyahu (Elijah) taught: Six thousand years is the duration of the world. Two thousand of the six thousand years are characterized by chaos; two thousand years are characterized by Torah, from the era of the Patriarchs until the end of the mishnaic period; and two thousand years are the period of the coming of the Messiah. Six thousand years is the duration of the world, and it is in ruins for one thousand years. The duration of the period during which the world is in ruins is derived from a verse, as it is stated: “And the Lord alone shall be exalted on that day” (Isaiah 2:11). That is the course that history was to take, but due to our many sins, the Messiah did not come after four thousand years passed, and furthermore, the years that elapsed since then, which were to have been the messianic era, have elapsed.
-Sanhedrin.97a.14, 97a.12, 97b.01
God said to Moses: ‘Command the children of Israel and say to them, My appointed times (moed) shall you keep as My covenant forever.’ (Leviticus 23:2) This is to teach you that the calendar and its festivals are set by the divine order and should not be tampered with. Do not look into or follow the calculations of those who stray from this path, for their times are not aligned with the divine will. Just as I have sanctified the Sabbath, so have I sanctified the months and the festivals for you.
-Midrash Tanchuma, Parashat Pinchas 13
Rabbi Jacob said: This world (age) is like a lobby before the Age to Come; prepare yourself in the lobby so that you may enter the banquet hall… He used to say: Better is one hour of repentance and good deeds in this age than all the life of the Age to Come; and better is one hour of bliss in the Age to Come than all the life of this age.
-Pirkei Avot 4:16-17
The sentence of the generation of the Flood lasted twelve months, the sentence of the Egyptians lasted twelve months, the sentence of Job lasted twelve months, the sentence of Gog of Magog lasts twelve months, the sentence of the wicked in Gehenna lasts twelve months. Nebuchadnezzar was three and a half years. Sennacherib was over three and a half years. Vespasian was three and a half years.
-Eikhah Rabbah 1:40
The Sages taught: During the tenure of Shimon HaTzaddik, the lot for God always arose in the High Priest’s right hand; after his death, it occurred only occasionally; but during the forty years prior to the destruction of the Second Temple, the lot for God did not arise in the High Priest’s right hand at all. So too, the strip of crimson wool that was tied to the head of the goat that was sent to Azazel did not turn white, and the westernmost lamp of the candelabrum did not burn continually.
-Yoma 39b:5