Sahih Muslim Book - 36, Hadith - 5360

حَدَّثَنَا أَبُو كُرَيْبٍ مُحَمَّدُ بْنُ الْعَلاَءِ ، حَدَّثَنَا وَكِيعٌ ، عَنْ فُضَيْلِ بْنِ غَزْوَانَ ، عَنْ أَبِي حَازِمٍ ، عَنْ أَبِي هُرَيْرَةَ ، أَنَّ رَجُلاً مِنَ الأَنْصَارِ بَاتَ بِهِ ضَيْفٌ ، فَلَمْ يَكُنْ عِنْدَهُ إِلاَّ قُوتُهُ وَقُوتُ صِبْيَانِهِ ، فَقَالَ لاِمْرَأَتِهِ: نَوِّمِي الصِّبْيَةَ ، وَأَطْفِئِ السِّرَاجَ ، وَقَرِّبِي لِلضَّيْفِ مَا عِنْدَكِ ، قَالَ: فَنَزَلَتْ هَذِهِ الآيَةُ {وَيُؤْثِرُونَ عَلَى أَنْفُسِهِمْ وَلَوْ كَانَ بِهِمْ خَصَاصَةٌ}.

It was narrated from Abu Hurairah that an Ansari man had a guest one night, and he did not have anything but food for himself and his children. He said to his wife: "Put the children to sleep and extinguish the lamp, then serve what you have to the guest." He said: "And this Verse was revealed: '...And give them (emigrants) preference over themselves even though they were in need of that.''