Sunan an-Nasa'i, Hadith 4228 ⓘ
It was narrated that Nubaishah said: "It was said to the prophet: 'During the Jahiliyyah we used to offer the 'Atirah.' He said: 'Slaughter for the sake of Allah, the Mighty and sublime, no matter what month it is; do good for the sake of Allah, the Mighty and sublime, and feed the poor."'
أَخْبَرَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ، عَنِ ابْنِ عَوْنٍ، قَالَ حَدَّثَنَا جَمِيلٌ، عَنْ أَبِي الْمَلِيحِ، عَنْ نُبَيْشَةَ، قَالَ ذُكِرَ لِلنَّبِيِّ صلى الله عليه وسلم قَالَ كُنَّا نَعْتِرُ فِي الْجَاهِلِيَّةِ . قَالَ " اذْبَحُوا لِلَّهِ عَزَّ وَجَلَّ فِي أَىِّ شَهْرٍ مَا كَانَ وَبَرُّوا اللَّهَ عَزَّ وَجَلَّ وَأَطْعِمُوا " .
also referenced under: Book 41, Hadith 7 (In-Book) & Volume 5, Book 41, Hadith 4233 (DarusSalam)