When one of you receives an invitation (for a meal), he should accept it. If he isn to fasting, he should eat, and if he is fasten, he should pray. Hisham said: The word salat means to pray (for him to Allah). Abu Dawud said: This tradition has also been narrated by Hafs b. Ghiyath from Hisham. (Using translation from Abū Dāʾūd 2460)   

قَالَ رَسُولُ اللهِ ﷺ «إِذَا دُعِيَ أَحَدُكُمْ إِلَى الدَّعْوَةِ فَلْيُجِبْ فَإِنْ كَانَ صَائِمًا فَلْيُصَلِّ وَإِنْ كَانَ مُفْطِرًا فَلْيَطْعَمْ»