أَخْبَرَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ، قَالَ حَدَّثَنَا بِشْرُ بْنُ الْمُفَضَّلِ، عَنْ يُونُسَ، عَنِ الْحَسَنِ، عَنْ صَعْصَعَةَ بْنِ مُعَاوِيَةَ، قَالَ لَقِيتُ أَبَا ذَرٍّ قُلْتُ حَدِّثْنِي ‏.‏ قَالَ نَعَمْ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَا مِنْ مُسْلِمَيْنِ يَمُوتُ بَيْنَهُمَا ثَلاَثَةُ أَوْلاَدٍ لَمْ يَبْلُغُوا الْحِنْثَ إِلاَّ غَفَرَ اللَّهُ لَهُمَا بِفَضْلِ رَحْمَتِهِ إِيَّاهُمْ ‏"‏ ‏.‏

It was narrated that Sa'sa'ah bin Mu'awiyah said: "I met Abu Dharr and said: 'Tell me a Hadith.' He said: the Messenger of Allah said: There are no two Muslims, three of whose children die before reaching puberty, but Allah will forgive them by virtue of His mercy towards them."' Translation Not Available

Book Ref: Sunan An Nisai Book 21 Hadith 1874
Web Ref:  Sunan An Nisai Vol 3 Book 21 Hadith 1875