Amr bin Shu'ayb narrates from his father, from his grandfather (may Allah be pleased with him), that he (peace and blessings be upon him) said: "Whoever becomes the guardian of an orphan's wealth, let him trade with it, and not leave it idle so that it is used up by the payment of zakah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10982
Yusuf bin Mahak (may Allah have mercy on him) said that the Messenger of Allah (peace and blessings be upon him) said: "In the wealth of the orphan," or he said: "In the wealth of the orphans, trade, so that the wealth is not used up by charity, that is, by paying zakah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10983
Abd al-Rahman bin al-Sa'ib (may Allah have mercy on him) said that Sayyiduna Umar (may Allah be pleased with him) said: Trade with the wealth of orphans, lest charity consume it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10984
Al-Hakam bin Abi al-As said that Sayyiduna Umar (may Allah be pleased with him) said: "Do you have any trade? I have an orphan's wealth that is about to be used up by the payment of zakah." I said: Yes. He said that he gave me ten thousand, and I was away with that wealth for some time. Then I returned to him, and he asked me about it: "What became of the wealth?" I said: It has become one hundred thousand. He said: "Return our wealth to us; we have no need of the trade."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10985
Al-Qasim bin Muhammad said: Sayyidah Aishah (may Allah be pleased with her) used to pay the zakah on our wealth, while it was being traded with in Bahrain.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10986
Nafi' (may Allah have mercy on him) said that Sayyiduna Ibn Umar (may Allah be pleased with them both) used to borrow the wealth of the orphans that was in his care, because he considered this safer for it against loss, and he also used to pay zakah from their wealth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10987