Sahih Muslim Book 31, Hadith Number 6119.

Chapter : Allah’s Apostle (may peace be upon him) invoked blessings upon the tribes of Ghifar and Aslam.

This hadith has been transmitted on the authority of Ibn Umar with a slight variation of wording (and the wording) that Allah’s Messenger (may peace be upon him) said this on the pulpit. This hadith has been reported on the authority of Ibn Umar but through another chain of transmitters.