When you are invited to a feast (even though it is) the leg of the sheep, you should accept it.
Sahih Muslim Book 16, Hadith 120
← Previous Hadith I heard Abdullah b. Umar (Allah be pleased with them) narrating that Allah's Messenger (ﷺ) 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.

Sahih Muslim Book 16, Hadith 119 Next Hadith → When any one of you is invited to a feast, he should accept it. He may eat if he likes, or he may abandon (eating) if he likes. Ibn Mathanni did not make mention of the word" feast".

Sahih Muslim Book 16, Hadith 121