What is the ruling on a Muslim man who performs all obligatory religious duties depriving his daughters of their lawful share of inheritance, but not his sons, and what is the ruling on daughters who do not demand their lawful right, and is it permissible for their husband to demand it on their behalf?

A Muslim must be just among his children, male and female, in what he gives them. If he fails to do so, he has committed an injustice and a sin, for the Prophet, peace and blessings be upon him, said: "Do not make me a witness, for I do not bear witness to injustice." The issue mentioned in the question – which deprives daughters of their rights – is more dangerous and resembles the actions of the people of Jahiliyyah (pre-Islamic ignorance). The father must repent to Allah and be just among his children, leaving the matter of inheritance to what Allah has legislated. Daughters have the right to demand their share, and if they forgo demanding it for fear of dispute, there is no blame upon them. Their husbands are not allowed to demand it on their behalf.