Sahih Muslim , Book 37, Hadith 6620 (USC-MSA)

Abu Sirma reported that when the time of the death of Abu Ayyub Ansari drew near, he said: I used to conceal from you a thing which I heard from Allah's Messenger and I heard Allah's Messenger as saying: Had you not committed sins, Allah would have brought into existence a creation that would have committed sin (and Allah) would have forgiven them.

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، عَنْ مُحَمَّدِ بْنِ قَيْسٍ، - قَاصِّ عُمَرَ بْنِ عَبْدِ الْعَزِيزِ - عَنْ أَبِي صِرْمَةَ، عَنْ أَبِي أَيُّوبَ، أَنَّهُ قَالَ حِينَ حَضَرَتْهُ الْوَفَاةُ كُنْتُ كَتَمْتُ عَنْكُمْ شَيْئًا سَمِعْتُهُ مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏ "‏ لَوْلاَ أَنَّكُمْ تُذْنِبُونَ لَخَلَقَ اللَّهُ خَلْقًا يُذْنِبُونَ يَغْفِرُ لَهُمْ ‏" ‏ ‏.‏

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