Hadith 148

Sahih Muslim

Book 1: The Book of Faith

Chapter 34

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

باب بَيَانِ نُقْصَانِ الإِيمَانِ بِنَقْصِ الطَّاعَاتِ وَبَيَانِ إِطْلاَقِ لَفْظِ الْكُفْرِ عَلَى غَيْرِ الْكُفْرِ بِاللَّهِ كَكُفْرِ النِّعْمَةِ وَالْحُقُوقِ

Sahih Muslim 79b
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.