Sahih Muslim 3019 a
Hisham reported on the authority of his father that 'A'isha said in connection with His (Allah's) words:
" And whoever is poor let him take reasonably (out of it)" that it was revealed in connection with the custodian of the property of an orphan, who is in charge of her and looks after her; In case he is poor, he is allowed to eat out of that.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدَةُ بْنُ سُلَيْمَانَ، عَنْ هِشَامٍ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، فِي قَوْلِهِ ‏{‏ وَمَنْ كَانَ فَقِيرًا فَلْيَأْكُلْ بِالْمَعْرُوفِ‏}‏ قَالَتْ أُنْزِلَتْ فِي وَالِي مَالِ الْيَتِيمِ الَّذِي يَقُومُ عَلَيْهِ وَيُصْلِحُهُ إِذَا كَانَ مُحْتَاجًا أَنْ يَأْكُلَ مِنْهُ ‏.‏