وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّهُ اشْتَرَى لِبَنِي أَخِيهِ - يَتَامَى فِي حَجْرِهِ - مَالاً فَبِيعَ ذَلِكَ الْمَالُ بَعْدُ بِمَالٍ كَثِيرٍ ‏.‏ قَالَ مَالِكٌ لاَ بَأْسَ بِالتِّجَارَةِ فِي أَمْوَالِ الْيَتَامَى لَهُمْ إِذَا كَانَ الْوَلِيُّ مَأْذُونًا فَلاَ أَرَى عَلَيْهِ ضَمَانًا ‏.‏

Yahya related to me from Malik that Yahya ibn Said bought someproperty on behalf of his brother's sons who were orphans in hishouse, and that that property was sold afterwards for a great deal ofprofit. Malik said, "There is no harm in using the propertyof orphans to trade with on their behalf if the one in charge of themhas permission. Furthermore, I do not think that he is under anyliability." Translation Not Available

Book Ref: Muwatta Imam Malik Book 17 Hadith 595
Web Ref:  Muwatta Imam Malik Book 17 Hadith 15