(a) It is narrated from Sayyiduna Anas (may Allah be pleased with him) that when he wiped his head, he would not turn his hair over.
(b) Abu Abdullah (Imam Ahmad, may Allah have mercy on him) said: This report and the report of Sayyidah Rubayyi' (may Allah be pleased with her) have one and the same meaning: he would not turn the hair over from its place.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 276