In the Book of Zakah and the Book of Sales it has already passed, as a mursal report from Yusuf bin Mahak (may Allah have mercy on him) from the Prophet (peace and blessings be upon him), and from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) as his own saying, that: "Seek (profit through trade) with the wealth of orphans, (lest) zakah consume it."
Habib bin Abi Thabit (may Allah have mercy on him) said that Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) had the wealth of an orphan with him, and he used to pay zakah on it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12675