Sayyiduna al-Miqdam al-Kindi (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "I am closer to every believer than his own self. Whoever leaves a debt or leaves dependent children, that is my responsibility, and whoever leaves wealth, it is for his heirs. I am the guardian of one who has no guardian: I inherit his wealth and I will free his captives. And the maternal uncle is the guardian of one who has no guardian: he will inherit his wealth and free his captives."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12210