بُلُوغُ الْمَرَامِ
Bulugh al-Maram 1039
Marriage
وَعَنْ اِبْنِ عُمَرَ - رَضِيَ اَللَّهُ عَنْهُمَا- قَالَ : قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ إِذَا دُعِيَ أَحَدُكُمْ إِلَى اَلْوَلِيمَةِ فَلْيَأْتِهَا } مُتَّفَقٌ عَلَيْهِ [1] .
Narrated Ibn 'Umar (RA): Allah's Messenger (ﷺ) said: "When one of you is invited to a wedding feast he must attend it." [Agreed upon].
Sunnah.com reference: Book 8, Hadith 87