Yahya related to me from Malik from Muhammad ibn Abi Bakr ibn Amribn Hazm from his father from Abu'n-Nadr as-Salami that the Messengerof Allah, may Allah bless him and grant him peace, said, "If three ofa muslim's children die, and he remains content with that, they willbe a protection for him from the Fire." A woman who was with theMessenger of Allah, may Allah bless him and grant him peace, said, "Ortwo, Messengerof Allah?", and he said, "Or two."
USC-MSA web (English) reference: Book 16, Hadith 39
Arabic reference: Book 16, Hadith 561