Sahih Muslim 1974
Salama b. al-Akwa' reported Allah's Messenger (way peace be upon him) having said:
He who sacrifices (animal) among you nothing should be left in his house (out of its flesh) on the morning of the third day. When it was the next year they (his Companions) said: Should we do this year as we did daring the previous year? Thereupon he said: Don't do that, for that was a year when the people were hard pressed (on account of poverty). so I wanted that the (flesh) might be distributed amongst them.
حَدَّثَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، أَخْبَرَنَا أَبُو عَاصِمٍ، عَنْ يَزِيدَ بْنِ أَبِي عُبَيْدٍ، عَنْ سَلَمَةَ،
 بْنِ الأَكْوَعِ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ مَنْ ضَحَّى مِنْكُمْ فَلاَ يُصْبِحَنَّ فِي
 بَيْتِهِ بَعْدَ ثَالِثَةٍ شَيْئًا ‏"‏ ‏.‏ فَلَمَّا كَانَ فِي الْعَامِ الْمُقْبِلِ قَالُوا يَا رَسُولَ اللَّهِ نَفْعَلُ كَمَا فَعَلْنَا
 عَامَ أَوَّلَ فَقَالَ ‏"‏ لاَ إِنَّ ذَاكَ عَامٌ كَانَ النَّاسُ فِيهِ بِجَهْدٍ فَأَرَدْتُ أَنْ يَفْشُوَ فِيهِمْ ‏"‏ ‏.‏