مَنْ كَانَ لَهُ شَعْرٌ فَلْيُكْرِمْهُ
Translation: Whoever has hair should care for it and keep it well.
Source: أبو داود
مَنْ كَانَ لَهُ شَعْرٌ means “whoever has hair”; لَهُ expresses possession. فَلْيُكْرِمْهُ uses the command particle to mean “let them care for it,” and the final pronoun refers back to the hair.
The instruction connects personal dignity with cleanliness and grooming. Washing, combing, and appropriate hair care can be parts of it. The objective is reasonable care, not vanity or needless expense.