Is it permissible to refuse to give money to one's father if he asks for it, as a means of compelling him to pray on time, knowing that he prays Fajr an hour or half an hour before Dhuhr?

The majority of scholars hold that a son is not obliged to give his father any of his wealth if the father is self-sufficient, unless he gives it voluntarily as an act of kindness. However, if the father is in need and has nothing to spend, then his maintenance is unanimously obligatory upon his son, even if he abandons prayer, based on the Almighty's saying: "And if they should strive to make you associate with Me that of which you have no knowledge, then do not obey them, but accompany them in [this] world with kindness and follow the way of those who turn back to Me. Then to Me is your return, and I will inform you about what you used to do." (Luqman: 15).

You should have a good opinion of your father. If he is overcome by sleep and cannot wake up, then there is no sin upon him if he takes the means that help him wake up, based on the Hadith of Abu Sa'id Al-Khudri, that Safwan ibn Al-Mu'attal said to the Prophet, peace and blessings be upon him: "And as for her saying that I do not pray until the sun rises, indeed we are a household for whom this is known, we hardly wake up until the sun rises. He said: 'When you wake up, then pray.'" And likewise, based on the Hadith of Abu Qatadah: "Indeed, there is no negligence in sleep. Negligence is only upon one who does not pray the prayer until the time of the next prayer comes. So whoever does that, let him pray it when he becomes aware of it."

If he sleeps after the prayer time has become narrow, then he is sinful for that.