Sahih Bukhari Volume 2, Book 23, Hadith 1250

حَدَّثَنَا مُسْلِمٌ، حَدَّثَنَا شُعْبَةُ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ الأَصْبَهَانِيِّ، عَنْ ذَكْوَانَ، عَنْ أَبِي سَعِيدٍ، رضى الله عنه أَنَّ النِّسَاءَ، قُلْنَ لِلنَّبِيِّ صلى الله عليه وسلم اجْعَلْ لَنَا يَوْمًا‏.‏ فَوَعَظَهُنَّ، وَقَالَ ‏"‏ أَيُّمَا امْرَأَةٍ مَاتَ لَهَا ثَلاَثَةٌ مِنَ الْوَلَدِ كَانُوا حِجَابًا مِنَ النَّارِ ‏"‏‏.‏ قَالَتِ امْرَأَةٌ وَاثْنَانِ‏.‏ قَالَ ‏"‏ وَاثْنَانِ ‏"‏‏

Narrated By Abu Sa'id : The women requested the Prophet, "Please fix a day for us." So the Prophet 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 replied, "Even two (would screen her from the (Hell) Fire. "