It was narrated that Anas bin Malik said:
"I saw the Messenger of Allah performing ablution, wearing a Qatari turban. He put his hand beneath the turban and wiped the front part of his head, and he did not take the turban off." (DE)
English reference (DE): Vol. 1, Book 1, Hadith 564 (DE)
Arabic reference (DE): Book 1, Hadith 607 (DE)