صَحِيحُ مُسْلِمٍ
Sahih Muslim 79 b
The Book of Faith
Clarifying that faith decreases with shortcoming in obedience, and the word Kufr may be used with regard to matters other than dsbelief in Allah, such as ingratitude for blessings and not fulfilling one's duties
وَحَدَّثَنِيهِ أَبُو الطَّاهِرِ، أَخْبَرَنَا ابْنُ وَهْبٍ، عَنْ بَكْرِ بْنِ مُضَرَ، عَنِ ابْنِ الْهَادِ، بِهَذَا الإِسْنَادِ مِثْلَهُ .
This hadith has been narrated on the authority of Abu Tahir with this chain of transmitters.
Sahih Muslim, 79 bSahihصحيح