As for the man who swore that he would not speak to his father, whatever oath he swears of the kinds sworn by Muslims, he must offer the expiation for an oath if he breaks it.

Whatever oath he has sworn, if he considers breaking it better than keeping it, he should offer expiation for his oath and break it, as the Quran and Sunnah indicate. This applies whether he swears by Allah’s name or invokes a vow, divorce, emancipation, zihār (declaring his wife forbidden to him like his mother), or a declaration that something is forbidden to him. For example, he might say: “If I do such-and-such, my wealth shall be given in charity, I shall be bound to perform ten pilgrimages and fast for a year, my wives shall be divorced, and my slaves shall be free,” or something similar. Expiation suffices for any oath of the kinds sworn by Muslims.

As for oaths that are not of these kinds—such as swearing by the Kaaba, shaykhs, kings, or forefathers—they are unlawful, nonbinding oaths and have no sanctity.

In the law prescribed by Allah and His Messenger, there are only two kinds of oath: a binding oath, which requires expiation, and a nonbinding oath, which entails nothing if it is broken.

Any scholar who affirms the existence of a binding oath that cannot be expiated holds a weak position, contrary to the Quran, the Sunnah, the statements of the Companions, and clear analogical reasoning. And Allah knows best.

He was also asked:

A man had children, both sons and daughters, and before his death he gave gifts to the daughters but not to the sons. Does any liability remain upon him, or not?