(22) باب وَمَا لِلْوَصِيِّ أَنْ يَعْمَلَ فِي مَالِ الْيَتِيمِ، وَمَا يَأْكُلُ مِنْهُ بِقَدْرِ عُمَالَتِهِ
Narrated `Aisha:
The following Verse:-- "If a guardian is well-off, let him claim no remuneration (i.e. wages), but if he is poor, let him have for himself what is just and reasonable." (4.6) was revealed in connection with the guardian of an orphan, and it means that if he is poor he can have for himself (from the orphan's wealth) what is just and reasonable according to the orphan's share of the inheritance.
Reference: Sahih al-Bukhari 2765
In-book reference: Book 55, Hadith 28
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 51, Hadith 27