Hadithcore
Mishkat al-Masabih, 1730

He reported God’s messenger as saying to some women of the Ansar, “None of you will lose three children by death and seek a reward from God without entering paradise.” One of them asked, “Or two, messenger of God?” He replied, “Or two.” Muslim transmitted it. Bukharl and Muslim have a version which says, “three who were not old enough to sin.”

وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لِنِسْوَةٍ مِنَ الْأَنْصَارِ:

لَا يَمُوتُ لِإِحْدَاكُنَّ ثَلَاثَةٌ من الْوَلَد فتحتسبه إِلَّا دخلت الْجنَّة. فَقَالَ امْرَأَةٌ مِنْهُنَّ: أَوِ اثْنَانِ يَا رَسُولَ اللَّهِ؟ قَالَ: أَوْ اثْنَانِ

. رَوَاهُ مُسْلِمٌ وَفِي رِوَايَةٍ لَهما: «ثَلَاثَة لم يبلغُوا الْحِنْث»

References1 variant
In-Book Reference
Book 5, Hadith 202