The ruling on one who swears by the forbidden that he will not have intercourse with his wife for a full year

Question:
Similarly, another question: A man became angry with his wife and swore an oath by the forbidden that he would not have intercourse with her for a full year. What is the ruling on this oath, and what is its expiation?

Answer:
By "the forbidden," he means that he will not have intercourse with her for a month, a year, a day, two years, or more. This falls under the ruling of an oath. However, if he says, "She is forbidden to me," meaning she is like his mother's back or his sister's back, then this falls under the ruling of zihar. It is forbidden for him until he frees a slave. If he cannot find one, he must fast for two consecutive months. If he is unable to do so, he must feed sixty poor people. But if he says, "It is forbidden for me to have intercourse with her," or "It is forbidden for me to speak to her," or "It is forbidden for me to sleep with her," then this falls under the ruling of an oath.