What is the ruling on deducting a portion of one's salary for life as expiation for an oath for someone who does not know how many times he has broken his oath, with the intention that this amount will cover past expiations and then become an ongoing charity?

If a person has made oaths and does not know the number of expiations required, he must estimate them in a way that absolves his responsibility. Then, for each oath, he must expiate by feeding ten poor persons, or clothing them, or freeing a slave. If he cannot find any of these, he should fast for three days for each oath. It is not a condition to perform them all at once; rather, it is permissible to perform them gradually. The majority of scholars do not consider it sufficient to pay the value of the expiation in cash, unless it is given to an agent who then uses it to purchase food. However, according to the view that allows paying the value, it is estimated at the average of what a person feeds his family, and at the local market price. A portion of the salary can be deducted for this, provided that the amount allocated for each poor person is not less than the value of his food. Anything in excess of the expiation is considered charity, but it is not considered an ongoing charity (sadaqah jariyah) in the jurists' conventional understanding.