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."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / Q12675
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
Al-Qasim bin Muhammad said: Sayyidah Aishah (may Allah be pleased with her) used to pay zakah on our wealth, while it was being traded with in Bahrain.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12676
Salim reports from Ibn Umar (may Allah be pleased with them both) that he used to have the wealth of orphans with him, and he would take it as a loan in order to protect it from being lost, and he would pay its zakah from their wealth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12677
A man from Hamdan came to Ibn Mas'ud (may Allah be pleased with him) on a piebald horse and said: A man has made me the executor of his will and has left an orphan; may I buy this horse, or another horse, from his wealth? Abdullah (may Allah be pleased with him) said: Do not buy anything from his wealth. And in the written record it reads: Do not buy anything from his wealth, and do not borrow anything from his wealth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12678