Abdullah bin Abbas (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) performed Qunoot (Nazilah) continuously for a month after each of the five prayers. When he would rise from the bowing (ruku') in the last rak'ah and say «سمع الله لمن حمده» , he would supplicate against the tribe of Banu Sulaym (Ra'l, Dhakwan), and the followers would say Ameen. The narrator says: He had sent them (preachers) to invite them to Islam, whom they killed. Ikrimah says: The practice of Qunoot (Nazilah) began from here.