What can an elderly man do if he is unable to fast, does not possess the means to feed or clothe ten indigent people, or free a slave, and wishes to break his oath concerning severing ties with his son? Can he fast three days despite his inability?

The fundamental principle is that whoever takes an oath and then sees that something else is better than it should expiate for his oath and do that which is better. If the oath was to commit a sin, then it is obligatory to break it. Cutting off ties of kinship is among the forbidden sins, and a man must maintain ties with his son's kin. If maintaining ties is not possible except by entering his house, then that becomes obligatory. If maintaining ties is possible without entering the house, then entering it at that point would be more preferable. Whenever the father breaks his oath, expiation becomes due upon him. It is permissible for his son or someone else to expiate on his behalf with his permission, or to borrow the cost of the expiation if he is able to repay it and finds someone to lend it to him.