Flavius Josephus, The Wars of the Jews
William Whiston, A.M., Ed.

[533] In the mean time, many of the principal men of the city were persuaded by Ananus, the son of Jonathan, and invited Cestius into the city, and were about to open the gates for him; but he overlooked this offer, partly out of his anger at the Jews, and partly because he did not thoroughly believe they were in earnest; whence it was that he delayed the matter so long, that the seditious perceived the treachery, and threw Ananus and those of his party down from the wall, and, pelting them with stones, drove them into their houses; but they stood themselves at proper distances in the towers, and threw their darts at those that were getting over the wall. Thus did the Romans make their attack against the wall for five days, but to no purpose. But on the next day Cestius took a great many of his choicest men, and with them the archers, and attempted to break into the temple at the northern quarter of it; but the Jews beat them off from the cloisters, and repulsed them several times when they were gotten near to the wall, till at length the multitude of the darts cut them off, and made them retire; but the first rank of the Romans rested their shields upon the wall, and so did those that were behind them, and the like did those that were still more backward, and guarded themselves with what they call Testudo, [the back of] a tortoise, upon which the darts that were thrown fell, and slided off without doing them any harm; so the soldiers undermined the wall, without being themselves hurt, and got all things ready for setting fire to the gate of the temple.