Sahih Muslim
The Book of Marriage (Kitab Al-Nikah)
Book Number: 008 / Hadith Number: 3344
Nafil reported: I heard Abdullah b. Umar (Allah be pleased with them) narrating that Allah's Messenger (may peace be upon him) said: Accept the feast when you are invited to it. And Abdullah (b. Umar) used to come to the feast, whether it was a wedding feast or other than that, and he would come there even in the state of fasting.