Sunan Ibn Majah, Volume 3, Book 9, Hadith 1908 (DarusSalam) ⓘ
It was narrated that Anas bin Malik said: “I never saw the Messenger of Allah give a wedding feast for any of his wives like the feast he gave for Zainab, for which he slaughtered a sheep.”
حَدَّثَنَا أَحْمَدُ بْنُ عَبْدَةَ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ ثَابِتٍ الْبُنَانِيِّ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ مَا رَأَيْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ أَوْلَمَ عَلَى شَىْءٍ مِنْ نِسَائِهِ مَا أَوْلَمَ عَلَى زَيْنَبَ فَإِنَّهُ ذَبَحَ شَاةً .
also referenced under: Hadith 1908 (Reference) & Book 9, Hadith 1983 (In-Book)