الادهان وترجيل الشعر
Regular application of oil to the hair and scalp as part of routine grooming, mentioned approvingly and contrasted with a neglected, disheveled appearance.
مَنْ كَانَ لَهُ شَعْرٌ فَلْيُكْرِمْهُ
“Whoever has hair should take care of it [with oil and grooming].” (meaning, not a literal translation)
A man came before the Prophet ﷺ with disheveled hair and he gestured that he should go and fix it (Muwatta Malik) — a directly observed correction rather than only a general statement, reinforcing that the guidance was meant to be practically applied, not left abstract.
Ibn al-Qayyim discusses hair oils as protecting against dryness and brittleness, within the same category as olive oil's benefit for skin. He treats hair care as part of the broader dignity-and-cleanliness theme that runs through several practices in the tradition, distinguishing intentional grooming from either excessive vanity or total neglect.
Hair and scalp oiling remains common practice across many cultures today, and certain oils (including some studied varieties) are recognized in modern dermatology for reducing dryness and improving hair manageability, though claims beyond basic conditioning benefit vary in evidence quality.