Abu Muslim (may Allah have mercy on him) says that once I was with Hazrat Salman Farsi (may Allah be pleased with him). He saw that a man had become impure and wanted to take off his socks. Hazrat Salman Farsi (may Allah be pleased with him) instructed him to wipe over his socks and turban, and to wipe the amount of his forehead, and said that I have seen the Noble Prophet (peace and blessings be upon him) wiping over his socks and head covering (turban).