Sahih Muslim 42
Sahih Muslim · Book 1: The Book of Faith · Clarifying the superiority of Islam, and what part of it is best
وَحَدَّثَنِيهِ إِبْرَاهِيمُ بْنُ سَعِيدٍ الْجَوْهَرِيُّ ، حَدَّثَنَا أَبُو أُسَامَةَ ، قَالَ حَدَّثَنِي بُرَيْدُ بْنُ عَبْدِ اللَّهِ ، بِهَذَا الإِسْنَادِ قَالَ سُئِلَ رَسُولُ اللَّهِ صلى الله عليه وسلم أَىُّ الْمُسْلِمِينَ أَفْضَلُ فَذَكَرَ مِثْلَهُ .
Ibrahim b. Sa'id al-Jauhari has narrated this hadith with the same words in addition to these. The Messenger of Allah (may peace and blessings be upon him) was asked as to who amongst the Muslims is better, and the rest of the hadith was narrated like this.