Al-Adab Al-Mufrad, Hadith 370 ⓘ
Jarir reported that the Prophet, may Allah bless him and grant him peace, said, "Allah Almighty will not show mercy to the person who does not show mercy to other people."
حَدَّثَنَا عُمَرُ بْنُ حَفْصٍ، قَالَ: حَدَّثَنَا أَبِي، قَالَ: حَدَّثَنَا الأَعْمَشُ قَالَ: حَدَّثَنِي زَيْدُ بْنُ وَهْبٍ قَالَ: سَمِعْتُ جَرِيرًا، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ: مَنْ لاَ يَرْحَمِ النَّاسَ لاَ يَرْحَمْهُ اللَّهُ عَزَّ وَجَلَّ.
also referenced under: Book 19, Hadith 9 (In-Book) & Book 19, Hadith 370 (English)