Muwatta Malik (Yahya)

Benefit:
One understanding derived from this statement is that wiping (masah) over the turban (pagri) alone is not valid; it should be removed, and then the hair should be wiped. Accordingly, Imam Malik rahimahullah is establishing this meaning from the forthcoming narrations.

The second understanding is that wiping solely over the turban is not valid; however, if some of the wiping is also done on the hair, then it is valid.

Imam Malik rahimahullah, Imam Shafi'i rahimahullah, and Imam Abu Hanifah rahimahullah do not hold the view that wiping over the turban alone is permissible, whereas Imam Ahmad rahimahullah does hold this view. In this issue, the preferred opinion is that wiping only the head, wiping only the turban, or wiping over a quarter of the head (i.e., the forelock) and completing the rest of the wiping over the turban—all are correct and permissible.
[نيل الاوطار: 257/1، تحفة الأحوذي: 358/1، الروضة الندية: 129/1]

In the narration of Hudhayfah ibn al-Yaman radi Allahu anhu:
«أَنَّهُ تَوَضَّأَ وَمَسَحَ بِنَاصِيَتِهِ وَعَلَى الْعِمَامَةِ»
That is, the Messenger of Allah sallallahu alayhi wa sallam performed ablution (wudu) and wiped over the front part of his head and over the turban. [مسلم: 274/81] Whereas in the narrations of Amr ibn Umayyah al-Damri radi Allahu anhu [بخاري: 205] and Hudhayfah ibn al-Yaman radi Allahu anhu himself [ترمذي: 100], it is established from the Messenger of Allah sallallahu alayhi wa sallam that he wiped over the turban alone.