Rabbi Yoḥanan said: What is the meaning of that which is written: “Happy is the man who fears always, but he who hardens his heart shall fall into mischief” (Proverbs 28:14)? Jerusalem was destroyed on account of Kamtza and bar Kamtza. The place known as the King’s Mountain was destroyed on account of a rooster and a hen. The city of Beitar was destroyed on account of a shaft from a chariot [rispak]. The Gemara explains: Jerusalem was destroyed on account of Kamtza and bar Kamtza. This is as there was a certain man whose friend was named Kamtza and whose enemy was named bar Kamtza. He once made a large feast and said to his servant: Go bring me my friend Kamtza. The servant went and mistakenly brought him his enemy bar Kamtza. The man who was hosting the feast came and found bar Kamtza sitting at the feast. The host said to bar Kamtza. That man is the enemy [ba’al devava] of that man, that is, you are my enemy. What then do you want here? Arise and leave. Bar Kamtza said to him: Since I have already come, let me stay and I will give you money for whatever I eat and drink. Just do not embarrass me by sending me out.

The host said to him: No, you must leave. Bar Kamtza said to him: I will give you money for half of the feast; just do not send me away. The host said to him: No, you must leave. Bar Kamtza then said to him: I will give you money for the entire feast; just let me stay. The host said to him: No, you must leave. Finally, the host took bar Kamtza by his hand, stood him up, and took him out. After having been cast out from the feast, bar Kamtza said to himself: Since the Sages were sitting there and did not protest the actions of the host, although they saw how he humiliated me, learn from it that they were content with what he did. I will therefore go and inform [eikhul kurtza] against them to the king. He went and said to the emperor: The Jews have rebelled against you. The emperor said to him: Who says that this is the case? Bar Kamtza said to him: Go and test them; send them an offering to be brought in honor of the government, and see whether they will sacrifice it. The emperor went and sent with him a choice three-year-old calf. While bar Kamtza was coming with the calf to the Temple, he made a blemish on the calf’s upper lip. And some say he made the blemish on its eyelids, a place where according to us, i.e., halakha, it is a blemish, but according to them, gentile rules for their offerings, it is not a blemish. Therefore, when bar Kamtza brought the animal to the Temple, the priests would not sacrifice it on the altar since it was blemished, but they also could not explain this satisfactorily to the gentile authorities, who did not consider it to be blemished. The blemish notwithstanding, the Sages thought to sacrifice the animal as an offering due to the imperative to maintain peace with the government. Rabbi Zekharya ben Avkolas said to them: If the priests do that, people will say that blemished animals may be sacrificed as offerings on the altar. The Sages said: If we do not sacrifice it, then we must prevent bar Kamtza from reporting this to the emperor. The Sages thought to kill him so that he would not go and speak against them. Rabbi Zekharya said to them: If you kill him, people will say that one who makes a blemish on sacrificial animals is to be killed. As a result, they did nothing, bar Kamtza’s slander was accepted by the authorities, and consequently the war between the Jews and the Romans began. Rabbi Yoḥanan says: The excessive humility of Rabbi Zekharya ben Avkolas destroyed our Temple, burned our Sanctuary, and exiled us from our land.