" إِذَا دُعِيَ أَحَدُكُمْ إِلَى طَعَامٍ وَهُوَ صَائِمٌ فَلْيَقُلْ: إِنِّي صَائِمٌ "
Abu Huraira reported God’s messenger as saying, “When one of you is invited to a meal at a time when he is fasting he should say he is fasting.” In a version he said, “When one of you receives an invitation he should accept it. If he is fasting he should pray, but if not, he should eat.” Muslim transmitted it.