“I once asked abu al-Hassan, Musa (a.s.), about the case of a man who had with him a certain amount of dinars that belonged to a person of his associates for which he took wariq (dirham) from him for his needs; and the rate on that day was seven and seven and a half dirham for dinar. The owner of the asset asked for a certain amount of wariq (dirham) for his needs and it was not present and he bought them for him from a money changer with this rate or so then the rate changed before they finalized the account until the wariq (dirham) became twelve dirhams for one dinar; if he could settle it with him and it was with the rate as it was at the beginning when he took possession which was seven and seven and a half for a dinar. He (the Imam) said, ‘When he gave wariq (dirham) to him equal to the amount of dinars it is not harmful how the rates are and it is not harmful . 555