It is narrated that on the day of the Battle of al-Ahzab, the Prophet (peace and blessings be upon him) placed the women inside one of the fortresses of Madinah. Hassan bin Thabit (may Allah be pleased with him) was a generous man, so he (peace and blessings be upon him) placed him inside along with the women as well and shut the door. Then a Jew came and sat at the door of the fortress. Sayyidah Safiyyah bint Abd al-Muttalib (may Allah be pleased with her) said: "O Hassan! Go down to this disbeliever and kill him." He said: "I will not put myself in danger against this disbeliever." So I wrapped a cloth around myself, took a stone, went down to him and cut off his head.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21174