Is expiation (kaffarah) obligatory for a husband who swore by Allah's Book (the Quran) not to have intercourse with his wife for two months, or is he only required to adhere to the period without intercourse?

The majority of scholars, including the four Imams, are of the view that a husband's oath to abstain from intercourse for less than four months does not constitute īlāʾ (a vow of abstinence). If the wife cannot endure the completion of this period, the husband must fulfill her desire and engage in intercourse, then expiate his oath. If she has no such desire, he has the choice to complete the period or to break it by engaging in intercourse and expiating his oath. The latter is preferable, based on the Prophet's (peace be upon him) saying: "By Allah, if Allah wills, I will not swear an oath and then see something better than it, except that I will do what is better and release myself from that oath."