Ezra 10:6

Then Ezra rose up from before the house of God, he left the place in the court where he had prayed, and went into the chamber of Johanan, the son of Eliashib, where he could meet the princes and elders of the Jews in private; and when he came thither, he did eat no bread nor drink water, keeping up an absolute fast as a sign of mourning, in order to impress all the others with the sincerity of his motives; for he mourned because of the transgression of them that had been carried away.