Zur'ah bin Abd al-Rahman bin Jarhad narrated from his father that Sayyiduna Jarhad (may Allah be pleased with him) was one of the People of the Suffah. He said: the Messenger of Allah (peace and blessings be upon him) sat with us while my thigh was uncovered, and he (peace and blessings be upon him) said: "Do you not know that the thigh is awrah?"
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 2130