Al-Adab Al-Mufrad, Book 19, Hadith 10 (In-Book) ⓘ
'Umar was heard to say, "Anyone who does not show mercy will not be shown mercy. Anyone who does not forgive will not be forgiven. Anyone who does not pardon will not be pardoned or protected."
حَدَّثَنَا حَجَّاجٌ، قَالَ: حَدَّثَنَا شُعْبَةُ قَالَ: أَخْبَرَنِي عَبْدُ الْمَلِكِ قَالَ: سَمِعْتُ قَبِيصَةَ بْنَ جَابِرٍ قَالَ: سَمِعْتُ عُمَرَ، أَنَّهُ قَالَ: مَنْ لاَ يَرْحَمُ لاَ يُرْحَمُ، وَلاَ يُغْفَرُ مَنْ لاَ يَغْفِرُ، وَلاَ يُعْفَ عَمَّنْ لَمْ يَعْفُ، وَلاَ يُوقَّ مَنْ لا يَتَوَقَّ.
also referenced under: Hadith 371 (Reference) & Book 19, Hadith 371 (English)