Mishkat al-Masabih 13 Marriage كتاب النكاح 129

وَعَنْهُ قَالَ: مَا أَوْلَمَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَلَى أَحَدٍ مِنْ نِسَائِهِ مَا أولم على زَيْنَب أولم بِشَاة

He said that God’s Messenger did not hold such a wedding-feast for any of his wives as he did for Zainab. He held a wedding-feast with a sheep. (Bukhari and Muslim.)