The Book of Faith
1/15. Chapter:
Clarification of those characteristics which, if a person attains them, he will find the sweetness of faith
Sahih Muslim
حَدَّثَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، أَنْبَأَنَا النَّضْرُ بْنُ شُمَيْلٍ، أَنْبَأَنَا حَمَّادٌ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِنَحْوِ حَدِيثِهِمْ غَيْرَ أَنَّهُ قَالَ " مِنْ أَنْ يَرْجِعَ يَهُودِيًّا أَوْ نَصْرَانِيًّا " .
A similar hadith has been reported on the authority of Anas (with another chain of transmitters) with the exception of these words: that he again becomes a Jew or a Christian.
Reference : Sahih Muslim 43cIn-book reference : Book 1, Hadith 74USC-MSA web (English) reference : Book 1, Hadith 69