مسند اسحاق بن راهويه
Musnad Ishaq Bin Rahwiya
كتاب اللباس و الزينة
Book of Clothing and Adornment
Men must cover their thighs as they are part of the awrah
Hadith Number: 715
اخبرنا یحی بن آدم، واسرائیل، عن ابی یحیی الثقات، عن مجاهد،عن ابن عباس، راٰی رسول اللٰه صلی اللٰه علیه وسلم فخذ رجل، فقال له: غط فخذك فان فخذ الرجل من عورتهٖ.
It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) saw a man's thigh, so he said to him: "Cover your thigh, for the thigh of a man is part of his 'awrah (private parts)."
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