Sayyiduna al-Aswad bin Sari' (may Allah be pleased with him) said: I was reciting poetry to the Prophet (peace and blessings be upon him), and I did not know his Companions, until a man came who was broad-shouldered and bald. I was told: Be quiet, be quiet. I said: "Alas! Who is this for whom I am being silenced in the presence of the Prophet (peace and blessings be upon him)?" I was told: This is Umar bin al-Khattab.
Hadith Referenceالمعجم الكبير للطبراني / العشرة / 49