"...But if he (the guardian) is poor, let him have for himself what is just and reasonable (according to his work). And when you release their property to them, take witness in their presence; and Allah is All-Sufficient in taking account." (V.4:6)
Reference
Sahih al-Bukhari 4575
In-book reference
Book 65, Hadith 97
USC-MSA web (English)
Vol. 6, Book 60, Hadith 99
Arabic Text
حَدَّثَنِي إِسْحَاقُ، أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، حَدَّثَنَا هِشَامٌ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ فِي قَوْلِهِ تَعَالَى {وَمَنْ كَانَ غَنِيًّا فَلْيَسْتَعْفِفْ وَمَنْ كَانَ فَقِيرًا فَلْيَأْكُلْ بِالْمَعْرُوفِ} أَنَّهَا نَزَلَتْ فِي مَالِ الْيَتِيمِ إِذَا كَانَ فَقِيرًا، أَنَّهُ يَأْكُلُ مِنْهُ مَكَانَ قِيَامِهِ عَلَيْهِ، بِمَعْرُوفٍ.