Abu Hassan (may Allah have mercy on him) said: I said to Sayyiduna Abu Hurayrah (may Allah be pleased with him): Two of my children have died, so narrate to me a hadith about this by which our hearts may be comforted concerning our dead. He said: Yes, yes! "Their little ones are the birds of Paradise. One of them will meet his parents, or he said: will meet his father, and will take hold of his hand, just as I am holding your garment, and he will not let go of him until Allah Almighty admits him into Paradise."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 7142