What is the ruling on the repentance of a thief who does not know the amount of what he stole, and how is his repentance completed?

Praise be to Allah, and may peace and blessings be upon His Messenger. Theft is a major sin, and Allah has prescribed a severe punishment for it in this world, as mentioned in the Qur'an. If someone commits this sin and Allah conceals it, they should not expose themselves, but rather hasten to sincere repentance, which includes true remorse, abandoning the sin, and resolving never to return to it.

Additionally, the thief must return the stolen property to its rightful owners or seek their forgiveness. If they do not know the exact amount stolen, they should make an effort to estimate what is most likely sufficient to clear their liability, then return it if possible. However, if finding the rightful owners is impossible or their identity is completely unknown, they may donate the amount on their behalf, as was done by Ibn Mas'ud (may Allah be pleased with him) when he could not locate the seller of a slave girl he had purchased—he donated the price to the poor instead.