What is the ruling of Islamic law on investing money acquired from selling alcohol in a permissible project, and how should this money be divided among family members, taking into consideration the funds collected by the youngest son as the founder and worker of the tavern and the one who paid his father's debts?

Unlawful money must be returned to its owner if known; otherwise, it must be disposed of. Some scholars permit keeping a portion of the unlawful money necessary for the repentant person's expenses, while a third group believes that the repentant person is not obliged to dispose of any of it, but should return the exact unlawful money to its owners if they are known, and keep the rest. This is what Ibn Taymiyyah decreed. The most preponderant view is to take only what suffices for one's needs and dispose of the remainder.