Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “If one of you is invited for a meal, let him respond. If he is fasting, let him pray for the host. If he is not fasting, let him eat.”
Source: Ṣaḥīḥ Muslim 1431
Grade: Sahih (authentic) according to Muslim
عَنْ أَبِي هُرَيْرَةَ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا دُعِيَ أَحَدُكُمْ فَلْيُجِبْ فَإِنْ كَانَ صَائِمًا فَلْيُصَلِّ وَإِنْ كَانَ مُفْطِرًا فَلْيَطْعَمْ
1431 صحيح مسلم كتاب النكاح باب الأمر بإجابة الداعي إلى دعوة