It is narrated from Abd al-Rahman bin Jarhad (may Allah have mercy on him) that the Prophet (peace and blessings be upon him) passed by his father, Sayyiduna Jarhad (may Allah be pleased with him), while he had his thigh uncovered, and he (peace and blessings be upon him) said: "Cover it, for it is part of the awrah."
Imam al-Tabarani (may Allah have mercy on him) said: "Only Ma'mar narrated this hadith from al-Zuhri, and only Sa'id from Ma'mar; Muhammad bin Sawa' is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الميم / 7811
Hadith Takhrij«أخرجه الطبراني فى «الكبير» برقم: 2145»