The Book of Faith
1/34. Chapter:
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
Sahih Muslim
وَحَدَّثَنِي الْحَسَنُ بْنُ عَلِيٍّ الْحُلْوَانِيُّ، وَأَبُو بَكْرِ بْنُ إِسْحَاقَ قَالاَ حَدَّثَنَا ابْنُ أَبِي مَرْيَمَ، أَخْبَرَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، قَالَ أَخْبَرَنِي زَيْدُ بْنُ أَسْلَمَ، عَنْ عِيَاضِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، عَنِ النَّبِيِّ صلى الله عليه وسلم ح
A hadith like this as narrated by Ibn 'Umar has also been transmitted by Abu Sa'id al-Khudri.
Reference : Sahih Muslim 80aIn-book reference : Book 1, Hadith 149USC-MSA web (English) reference : Book 1, Hadith 142