At a banquet in the academy of Rabbi Yehuda HaNasi, the great redactor of the Mishnah around 200 CE, the wine flowed a little too freely. The sons of Rabbi Chiya, two brothers of startling sharpness named Yehudah and Chizkiyah, had drunk enough to say out loud what no one says sober.
They announced, according to the Talmud in Sanhedrin 38a, that the ben David, the descendant of David who would be the Messiah, would not come until the two princely houses of Israel had both ended. The two houses meant the Reish Galuta, the Exilarchate of Babylon, which ruled the Jewish diaspora community in Babylonia as an officially recognized royal line tracing itself back to King David, and the Nasi, the patriarchal dynasty in the Land of Israel, which Rabbi Yehuda HaNasi himself led, also tracing itself to Hillel and from Hillel to David. Both houses, the brothers said, had to fall. Only then would the true ben David rise and take their place.
Rabbi Yehuda HaNasi, listening, understood exactly what was being said at his own table. Two drunk young men had just predicted the end of his family. He is said to have responded, in that long moment, that the boys were speaking like minim, sectarians who wished for the fall of their own dynasty. But sober or drunk, the statement stuck in the tradition's memory, because it contained a hard truth that later generations would recognize.
Both houses did fall, eventually. The Exilarchate in Babylon lasted until around the eleventh century and then faded. The Nasi dynasty in the Land of Israel ended in the early fifth century. The Messiah has not yet come, but the Rabbis who preserved this exemplum, preserved as number 297 in Moses Gaster's 1924 Exempla of the Rabbis, felt its logic. Sometimes existing institutions, even noble ones, take up the place that ultimate redemption will require. Until they clear the stage, the ben David has nowhere to stand.