How can one atone for taking extra money from one's father to buy clothes and study materials, knowing that the father used to give money for clothes but it was not enough, and the father cannot be confronted with the matter for fear of problems?

The fundamental principle is that it is impermissible for children to take from their parents' wealth without their permission. An exception to this is if the parent is miserly and does not spend on his child the religiously mandated necessary maintenance. In such a case, the child may take what is sufficient for him in a reasonable manner, based on the saying of the Messenger of Allah, peace and blessings be upon him, to Hind bint Utbah: "Take what is sufficient for you and your child in a reasonable manner."

The obligatory maintenance is for necessities and does not include luxuries.

If money was taken unlawfully, it must be returned to the father by any appropriate means without informing him of the reality of what occurred. There is no need to dispose of clothes if the unlawful act pertains to the individual's accountability.

The fundamental principle is the prohibition of lying. However, lying is permissible if it is the only way to attain a right, such as a person lying to himself or to others if it does not involve harm to that other person and enables him to achieve his right.