(29) باب حِفْظِ اللِّسَانِ لِلصَّائِمِ
Abu Huraira (Allah be pleased with him) reported:
When any one of you gets up in the morning in the state of fasting, he should neither use obscene language nor do any act of ignorance. And if anyone slanders him or quarrels with him, he should say:" I am fasting, I am fasting."
Reference: Sahih Muslim 1151 a
In-book reference: Book 13, Hadith 209
USC-MSA web (English) reference(deprecated numbering scheme): Book 6, Hadith 2563