Sahih
حَدَّثَنَا مُحَمَّدُ بْنُ كَثِيرٍ، أَخْبَرَنَا سُفْيَانُ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ دُعِيَ فَلْيُجِبْ فَإِنْ شَاءَ طَعِمَ وَإِنْ شَاءَ تَرَكَ " .
Jabir reported the Messenger of Allah(ﷺ) as sayings:when one of you is invited to a meal, he must accept. If he wishes he may eat, but if he wishes(to leave), he may leave