Al-Adab Al-Mufrad, Hadith 391 ⓘ
Abu'd-Darda' reported that the Prophet, may Allah bless him and grant him peace, said, "Shall I tell you a degree better than prayer, fasting and sadaqa?" "Yes," they replied. He went to say, Improving a state of friendship. Causing discord in a state of friendship is what shaves things away."
حَدَّثَنَا صَدَقَةُ، قَالَ: حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ عَمْرِو بْنِ مُرَّةَ، عَنْ سَالِمِ بْنِ أَبِي الْجَعْدِ، عَنْ أُمِّ الدَّرْدَاءِ، عَنْ أَبِي الدَّرْدَاءِ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ: أَلاَ أُنَبِّئُكُمْ بِدَرَجَةٍ أَفْضَلَ مِنَ الصَّلاَةِ وَالصِّيَامِ وَالصَّدَقَةِ؟ قَالُوا: بَلَى، قَالَ: صَلاَحُ ذَاتِ الْبَيْنِ، وَفَسَادُ ذَاتِ الْبَيْنِ هِيَ الْحَالِقَةُ.
also referenced under: Book 21, Hadith 7 (In-Book) & Book 21, Hadith 391 (English)