The Prophet ﷺ said, "A Muslim whose three children die before the age of puberty will be granted Paradise by Allah due to his mercy for them."  

قَالَ النَّبِيُّ ﷺ مَا مِنَ النَّاسِ مِنْ مُسْلِمٍ يُتَوَفَّى لَهُ ثَلاَثٌ لَمْ يَبْلُغُوا الْحِنْثَ إِلاَّ أَدْخَلَهُ اللَّهُ الْجَنَّةَ بِفَضْلِ رَحْمَتِهِ إِيَّاهُمْ  

The women requested the Prophet, "Please fix a day for us." So the Prophet ﷺ preached to them and said, "A woman whose three children died would be screened from the Hell Fire by them," Hearing that, a woman asked, "If two died?" The Prophet ﷺ replied, "Even two (would screen her from the (Hell) Fire. " And Abu Huraira added, "Those children should be below the age of puberty. "  

أَنَّ النِّسَاءَ قُلْنَ لِلنَّبِيِّ ﷺ اجْعَلْ لَنَا يَوْمًا فَوَعَظَهُنَّ وَقَالَ أَيُّمَا امْرَأَةٍ مَاتَ لَهَا ثَلاَثَةٌ مِنَ الْوَلَدِ كَانُوا حِجَابًا مِنَ النَّارِ قَالَتِ امْرَأَةٌ وَاثْنَانِ قَالَ وَاثْنَانِ وَقَالَ شَرِيكٌ عَنِ ابْنِ الأَصْبَهَانِيِّ حَدَّثَنِي أَبُو صَالِحٍ عَنْ أَبِي سَعِيدٍ وَأَبِي هُرَيْرَةَ ؓ عَنِ النَّبِيِّ ﷺ قَالَ أَبُو هُرَيْرَةَ لَمْ يَبْلُغُوا الْحِنْثَ  

The Prophet ﷺ said, "No Muslim whose three children died will go to the Fire except for Allah's oath (i.e. everyone has to pass over the bridge above the lake of fire)."  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَمُوتُ لِمُسْلِمٍ ثَلاَثَةٌ مِنَ الْوَلَدِ فَيَلِجَ النَّارَ إِلاَّ تَحِلَّةَ الْقَسَمِ قَالَ أَبُو عَبْدِ اللَّهِ {وَإِنْ مِنْكُمْ إِلاَّ وَارِدُهَا}