Sayyiduna Anas bin Malik (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "There is no Muslim whose three children die before reaching puberty but Allah will admit him into Paradise by the grace of His mercy."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 7139