If someone steals something and does not know the owner's whereabouts in order to return it, is it permissible for him to give the value of the stolen item as a charitable endowment (sadaqah jariyah) on behalf of the owner? If it is not permissible, what should he do? And can he send the value of the stolen item instead of going in person?

Theft is a grave major sin, and its punishment is the cutting off of the hand. Repentance from it involves returning the right to its owner. If the stolen item is still present, it must be returned. If direct return is difficult, it can be delivered through stratagem. If its owner or their whereabouts cannot be known, then its value should be given in charity on their behalf, with a guarantee to them should the rightful owner be found later. The owner then has the choice between endorsing the charity or taking their right. Enduring charity (sadaqah jariyah) with the value of the stolen item is better because its reward is continuous.