Abu al-Tufayl said: I mentioned to Ibn Mas'ud (may Allah be pleased with him) a statement of Ali (may Allah be pleased with him), and he said: "Have you not seen his head? It was like a basin (shining), and around it there was only (hair) like a fringe."
Hadith Referenceالمعجم الكبير للطبراني / العشرة / 159