مُوَطَّأُ مَالِكٍ
Muwatta Malik 1144
Marriage
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ إِذَا دُعِيَ أَحَدُكُمْ إِلَى وَلِيمَةٍ فَلْيَأْتِهَا .
Yahya related to me from Malik from Nafi from Abdullah ibn Umar that the Messenger of Allah, (ﷺ), said, "When you are invited to a wedding feast, you must go to it."
Arabic/English book reference: Book 28, Hadith 49