وَيُغْسَلُ رَأْسُهُ وَلِحْيَتُهُ بِالْخِطْمِيِّ
Translation: Wash the hair of the head and the beard with khitmi.
Khitmi is a plant-based cleansing agent used on hair and beard. The purpose is to clean these areas thoroughly and ensure water reaches the relevant surfaces.