New Testament

Matthew 24:36-44

36 “But as for that day and hour no one knows it—not even the angels in heaven—except the Father alone. 37 For just like the days of Noah were, so the coming of the Son of Man will be. 38 For in those days before the flood, people were eating and drinking, marrying and giving in marriage, until the day Noah entered the ark. 39 And they knew nothing until the flood came and took them all away. It will be the same at the coming of the Son of Man. 40 Then there will be two men in the field; one will be taken and one left. 41 There will be two women grinding grain with a mill; one will be taken and one left.

42 “Therefore stay alert because you do not know on what day your Lord will come. 43 But understand this: If the owner of the house had known at what time of night the thief was coming, he would have been alert and would not have let his house be broken into. 44 Therefore you also must be ready because the Son of Man will come at an hour when you do not expect him.

Rabbinic

Sanhedrin 97b

The Gemara asks: What is the meaning of the phrase “And it declares [veyafe’aḥ] of the end, and does not lie”? Rabbi Shmuel bar Naḥmani says that Rabbi Yonatan says: May those who calculate the end of days be cursed [tippaḥ], as they would say once the end of days that they calculated arrived and the Messiah did not come, that he will no longer come at all. Rather, the proper behavior is to continue to wait for his coming, as it is stated: “Though it tarry, wait for it.” Lest you say we are expectantly awaiting the end of days and the Holy One, Blessed be He, is not awaiting the end of days and does not want to redeem His people, the verse states: “And therefore will the Lord wait, to be gracious to you; and therefore will He be exalted, to have mercy upon you; for the Lord is a God of judgment; happy are all they who wait for Him”