Is it permissible to use money acquired through fraud and deception, in which the father involved his son when he was young, to overcome a financial hardship, in accordance with the principle "Necessities permit the forbidden"?

It is not permissible to obey a created being in disobeying the Creator. Repentance does not nullify the rights of people; rather, injustices must be rectified and returned to them. The principle "necessities permit the forbidden" does not permit dealing with usury (riba). Whatever calamities befall a person are due to their sins, so that they may repent from them. Among the conditions of repentance is returning money to its owners or seeking their absolution. If it is impossible to identify them or if the money is public, then it must be given as charity to the poor and needy or spent on general charitable causes. It is not permissible to take unlawful money to alleviate distress; instead, rights must be returned to their owners, and one must rely upon Allah, and the father should be advised to repent.