What is the ruling of Islamic law concerning a Muslim man who does not order his daughters to wear the hijab, even though they wear modest clothing, but do not cover their hair?

What is required of a Muslim extends beyond the Five Pillars of Islam; he must comply with commands and avoid prohibitions. Among the foremost of his duties is to protect himself and his family from that which incurs Allah's wrath, for a man is responsible for those under his care. A woman uncovering her hair is one of the worst forms of tabarruj (displaying oneself immodestly), and condoning this invalidates a man's testimony, indicates a loss of his manhood, a lack of chivalry, and an abandonment of his responsibility. A man must command those under his guardianship to observe complete hijab to preserve their honor and safeguard their chastity. Jealousy (ghira) is a characteristic of a believer, which is that a believer would commit what Allah has forbidden for him, and its opposite is dayatha (cuckoldry), where one does not feel jealousy over his female kin. He must fear Allah regarding himself and his family and command his daughters to observe covering (satr) and modesty (ihtisham).