It wasnarrated from Abu Hurairah that the Messenger of Allah (ﷺ)said:
"When anyone of you is fasting, let him not utter evil orignorantspeech. If anyone speaks to him in an ignorant manner, lethim say:'I am fasting.'" (JA)
English reference (JA): Vol. 1, Book 7, Hadith 1691 (JA)
Arabic reference (JA): Book 7, Hadith 1761 (JA)