How does piety affect the disposal of a large amount of unlawful wealth mixed with lawful wealth?

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When a large amount of unlawful wealth is mixed with lawful wealth, such as ten unlawful Dirhams among two hundred lawful ones, the obligation is to give away the unlawful portion, as restitution removes the prohibition. However, due to the hardship involved in identifying and separating the entire unlawful portion, piety (wara') is relaxed, and only the obligatory restitution is required. The ease of giving away the entire unlawful portion depends on the individual's circumstances; if a person has little wealth, giving away even a small unlawful amount may cause hardship due to need, whereas a wealthy person can more easily dispose of it.