Sunan an-Nasa'i 104
سنن النسائي#104SahihIt was narrated that Bilal said:"I saw the Prophet (ﷺ) wiping over the Khuff and the Khimar." [1] A head covering not limited to the common usage of "turban" as is clear from the first narration
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 1:104