Sayyiduna al-Harith bin Uqaysh al-Ukli (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) say: "Any Muslim man and Muslim woman who lose four children who had not yet reached puberty, Allah will admit them into Paradise." Then he related the same as mentioned before.
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 3349