Riyad as-Salihin, Book 3, Hadith 738 (In-Book)

Abu Hurairah (May Allah be pleased with him) reported: Messenger of Allah 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].

عن أبى هريرة رضى الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم ‏:‏ ‏ "‏إذا دعي أحدكم ، فليجب، فإن كان صائما فليصل، وإن كان مفطراً فليطعم‏" ‏ ‏.‏

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