Sunan Abi Dawud, Hadith 4715

Abu Dawud said : Malik was asked : The heretics argue from this tradition against us. Malik said : Argue against them from its last part which goes. The people asked : What do you think about the one who died while he was young? He replied : Allah knows best what he was going to do.

قَالَ أَبُو دَاوُدَ قُرِئَ عَلَى الْحَارِثِ بْنِ مِسْكِينٍ وَأَنَا أَسْمَعُ، أَخْبَرَكَ يُوسُفُ بْنُ عَمْرٍو، أَخْبَرَنَا ابْنُ وَهْبٍ، قَالَ سَمِعْتُ مَالِكًا، قِيلَ لَهُ إِنَّ أَهْلَ الأَهْوَاءِ يَحْتَجُّونَ عَلَيْنَا بِهَذَا الْحَدِيثِ ‏.‏ قَالَ مَالِكٌ احْتَجَّ عَلَيْهِمْ بِآخِرِهِ ‏.‏ قَالُوا أَرَأَيْتَ مَنْ يَمُوتُ وَهُوَ صَغِيرٌ قَالَ ‏ "‏ اللَّهُ أَعْلَمُ بِمَا كَانُوا عَامِلِينَ ‏" ‏ ‏.‏

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also referenced under: Hadith 4697 (Hasan)