The Imama (Turban) has been mentioned in numerous hadiths. Imam Tirmidhi has dedicated a separate chapter to hadiths about the imama (turban) in his book شمائل ترمذی
It is narrated from Ibn Umar (may Allah be pleased with him) that:
“When the Prophet (peace be upon him) put on his imama (turban), he used to let its loose end hang down between his shoulders.”
Wearing the imama (turban) is categorised as one of the “Sunan Aadyah” (a Sunnah that was a habit of the Prophet SAW), meaning that wearing the imama (turban) is a source of rewards and blessings, but not wearing it does not incur any sin or punishment.