He was also asked—may Allah have mercy on him—about someone who says:

“I undertake to pay such-and-such an amount for it, even if, for example, locusts devour it.”

He answered:

This condition is invalid, for it involves undue uncertainty and gambling. If he has taken it under contract for a payment subject to this condition, that payment would be less than the fair equivalent payable without the condition. According to the well-known view, a distinction must then be made according to whether the contract is valid or invalid. If the contract is invalid, whatever was received under it, or its value, must be returned. If it is valid, the portion of the stipulated payment corresponding to the surviving produce is increased proportionately by the difference between the value with the condition and the value without it.

For example, if the stipulated payment was one thousand and one third of the fruit remained, the share corresponding to it would be one third of what remained of the thousand. The value of the whole subject to the condition is then considered, taking nine hundred . . . (1) one thousand two hundred; one third of it is then added to the stipulated payment and to its share. And Allah knows best.