It is said that Shas ibn Qays, the Jew, passed by a group of the Ansar from the Aws and Khazraj who were conversing. This angered him because they had come together after the enmity that existed between them in the days of ignorance. He said: 'What do we have with them when they gather together?' He commanded a young man from the Jews to sit with them and remind them of the Day of Bi'ath and recite some of the poetry said about it. It was a day when the Aws and Khazraj fought, and the Aws were victorious. The young man did so, and then the people began to dispute and boast, and they became angry and said: 'Weapons, weapons!' The news reached the Prophet, blessings and peace be upon him, and he went out to them with some of the Emigrants and the Ansar. He said: 'Are you calling to the days of ignorance while I am among you after Allah has honored you with Islam and cut off the matter of ignorance from you and united your hearts?' The people recognized that it was a provocation from the devil and a plot from their enemy. They threw down their weapons, wept, and embraced one another. Then they returned with the Messenger of Allah, blessings and peace be upon him. There was no day that was worse at first and better in the end than that day.