A woman came to the Messenger of Allah ﷺ with a son of hers who was ill and said, "Messenger of Allah, I fear for him, and I have already lost three before him."The Messenger of Allah ﷺ said, "You have indeed built yourself a strong barrier against the Fire."
أخبرنا إسحق قال أنبأنا جرير قال حدثني طلق بن معاوية وحفص بن غياث قال حدثني جدي طلق بن معاوية عن أبي زرعة
جاءت امرأة إلى رسول الله ﷺ بابن لها يشتكي فقالت يا رسول الله أخاف عليه وقد قدمت ثلاثة فقال رسول الله ﷺ لقد احتظرت بحظار شديد من النار
Muslim narrated it in the Book of Righteousness and Kinship Ties, in the chapter on the merit of one whose child dies and he bears it with patience seeking Allah's reward, Hadith 2636, from the hadith of Jareer bin Abdul-Hameed, with this wording. It is also found in Kubra, Hadith 2000.