The Prophet (r) talked to them, read some of the Qur’an and invited them to accept Is-
lam. Then he said, “I invite your allegiance on a condition that you would protect me in the
same way as you would your women and children.” They gave allegiance to the Prophet (r)
but demanded that he would not leave them nor return to his own people. The Prophet (r)
then said in reply, “I am of you and you are of me. I will fight against them that make war
upon you and have peace with those that keep peace with you.”
Thereafter the Prophet (r) selected twelve of them, nine from the Khazraj and three from
the Aus, as their leaders. (Ibn Hisham, Vol. I, pp. 436-38)