Yahya said that he heard Malik speak about a man who bought goods- animals or clothes or wares, and the sale was found not to bepermitted so it was revoked and the one who had taken the goods wasordered to return the owner his goods. Malik said, "The owner of thegoods only has their value on the day they were taken from him, andnot on the day they are returned to him. That is because the man isliable for them from the day he took them and whatever loss is in themafter that is against him. For that reason, their increase and growthare also his. A man may take the goods at a time when they are sellingwell and are in demand, and then have to return them at a time whenthey have fallen in price and no one wants them. For instance, the manmay take the goods from the other man, and sell them for ten dinars orkeep them while their price is that. Then he may have to return themwhile their price is only a dinar. He should not go off with ninedinars from the man's property. Or perhaps they are taken by the man,and he sells them for a dinar or keeps them, while their price is onlya dinar, then he has to return them, and their value on the day hereturns them is ten dinars. The one who took them does not have to paynine dinars from his property to the owner. He is only obliged to paythe value of what he took possession of on the day it was taken ."He said, "Part of what clarifies this is that when a thiefsteals goods, only their price on the day he stole them is looked at.If cutting off the hand is necessary because of it, that is done. Ifthe cutting off is delayed, either because the thief is imprisoneduntil his situation is examined or he flees and then is caught, thedelay of the cutting off of the hand does not make the hadd, which wasobliged for him on the day he stole, fall from him even if those goodsbecome cheap after that. Nor does delay oblige cutting off the hand ifit was not obliged on the day he took those goods, even if they becomeexpensive after that."
USC-MSA web (English) reference: Book 37, Hadith 6