Abu Hurairah (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "When any of you is invited to a meal, he should accept the invitation. If he is observing Saum (fasting), he should supplicate for the betterment of the host and if he is not fasting, he should eat."[Muslim]. (AR)
App reference (AR): Book 3, Hadith 11 (AR)
Arabic/English book reference (AR): Book 3, Hadith 738 (AR)