Sahih
Muslim
صحيح مسلم
01
The Book of Faith
كتاب الإيمان
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 79 b
This hadith has been narrated on the authority of Abu Tahir with this chain of transmitters.
وَحَدَّثَنِيهِ أَبُو الطَّاهِرِ، أَخْبَرَنَا ابْنُ وَهْبٍ، عَنْ بَكْرِ بْنِ مُضَرَ، عَنِ ابْنِ الْهَادِ، بِهَذَا الإِسْنَادِ مِثْلَهُ .
Grade: Sahih