The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fada'il Al-Sahabah)
Muslim :: Book 31 : Hadith 6130
Abu Bakra reported on the authority of his father that Allah's Messenger (may peace be upon him) said: What is your view if Juhaina, Aslam, Ghifar were better than Banu Tamim, Banu 'Abdullah b. Ghatfan and 'Amir b. Sa'sa'a' respectively (then what would be status of the latter one)? He said this in a loud voice. They said: Allah's Messenger, they would be definitely at a loss and disadvantage. Thereupon he said: They (the first group) are decidedly better than the others; and in the hadith transmitted on the authority of Abu Kuraib the words are: It you were to find that Juhaina, Muzaina and Aslam and Ghifar (are better than...).