Dua When Declining Food While Fasting (Invocation for someone who offers you food when you are fasting, which you decline)

((إِذَا دُعِيَ أَحَدُكُمْ فَلْيُجِبْ، فَإِنْ كَانَ صَائِماً فَلْيُصَلِّ، وَإِنْ كَانَ مُفْطِراً فَلْيَطْعَمْ)) ، وَمَعْنَى فَلْيُصَلِّ أَيْ فَلْيَدْعُ

If you are invited to a meal, accept the invitation. If you are fasting, supplicate for the host; if you are not fasting, eat.