Arabic (Original)
و قَالَ أَسْوَدُ بِهَذَا الْإِسْنَادِ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا كَانَ يَوْمُ صَوْمِ أَحَدِكُمْ فَلَا يَرْفُثْ وَلَا يَفْسُقْ وَلَا يَجْهَلْ فَإِنْ جُهِلَ عَلَيْهِ فَلْيَقُلْ إِنِّي امْرُؤٌ صَائِمٌ.
English Translation
The Messenger of Allah (peace be upon him) said: "When it is a day of fasting for one of you, let him not engage in obscene speech, sinful conduct, or ignorant behavior. If someone behaves ignorantly toward him, let him say: 'I am a person who is fasting.'"