Palestinian Talmud, Ta'anit 4.5

Simon ben Kosiba, surnamed Simon bar Kochba ("son of the star") was a Jewish Messiah. Between 132 and 135, he was the leader of the last resistance against the Romans. After the end of the disastrous rebellion, the rabbis called him "Bar Kozeba", which means "son of the lie". This is mentioned in the Palestine Talmud, Ta'anit 4.5 and Midrash Rabbah Lamentations‚Äč 2.2.4, offered here in the translation by Craig Evans.

Palestine Talmud, Ta'anit 4.5

[4.5] Rabbi Simeon ben Yohai taught: Aqiba, my master, used to interpret a star goes forth from Jacobnote as "Kozeba goes forth from Jacob". Rabbi Aqiba, when he saw Bar Kozeba, said: "This is the king Messiah!" Rabbi Johanan ben Torta said to him: "Aqiba! Grass will grow on your cheeks and still the son of David does not come!"