Sahih Muslim Book 32, Hadith Number 6366.

Chapter : The merit of one who resigns himself to the will of God calmly at the time of the death of one’s son.

This hadith has been reported by Zuhri on the authority of Malik, and in the hadith transmitted on the authority of Sufyan (the words are): “He would enter into Fire, except for the fulfilment of the oath.”