Chapter on Conditioning Guardianship with a Condition

Question:
It is not permissible to condition agency with a condition, just as it is permissible to condition guardianship and authority with a condition. It is authentically reported from the Prophet (peace and blessings be upon him) that he conditioned authority with a condition, which is agency, delegation, and appointment. There is no concern whatsoever in conditioning agency with a condition, and the method is to validate it.

Answer:
He expressed doubt about it. So if he says, "You are my agent if so-and-so dies, and so-and-so is appointed over his farm," he says, "If he dies or becomes unable, then you are my agent for that," there is no harm in it, because this matter contains no excessive uncertainty or risk. It is like what the Prophet (peace and blessings be upon him) did when he sent the commanders on the expedition of Mu'tah and appointed Zayd ibn Harithah over them, saying, "If he is killed, then your commander is Ja'far ibn Abi Talib." May Allah have mercy on him. This is something that benefits and does not harm. Conditioning in such cases does not harm, just as a testator might bequeath a third to two people, saying, "If I die, then it is for my children, or for so-and-so's child, or so-and-so." There is no blame in that.