Is one who takes an oath bound by the intention of the one for whom the oath is taken, especially if there is a difference in the intention of the wording between the one who takes the oath and the one for whom it is taken? And do I owe an expiation for an oath if I break my fast at the homes of my married siblings more than four times?

It is not permissible to interpret an oath, and it is not considered valid. Some scholars stipulate that the one swearing the oath must be an oppressor or denying the truth, and that the ruler must administer the oath. Interpretation is permissible for one who is not an oppressor. You must answer the invitation of your brothers, and an oath should not prevent you from acts of righteousness.