What is the ruling regarding a man telling his wife "It is forbidden for me to sleep with you" three times out of anger, knowing that he did not intend divorce?

It is not permissible for the wife to refuse intercourse without a valid excuse, based on the saying of the Prophet (peace be upon him): "If a man invites his wife to his bed and she refuses, and he spends the night angry with her, the angels curse her until morning."

If the husband says to his wife, "It is forbidden for me to sleep with you," and he intends only to forbid sleeping, not intercourse, then this is considered a prohibition of what is lawful, and an oath is constituted by it. An expiation for a broken oath becomes obligatory if he violates it. If he intends to forbid intercourse with her permanently or for more than four months, this is an ila' (vow of abstinence). The wife then has the option to accept remaining without intercourse, or to refer her case to the judge, who will order either divorce or intercourse. If you have intercourse with her before the period expires, an expiation for a broken oath becomes obligatory upon you.

If he intends zihar (a pronouncement comparing his wife to an unmarriageable female relative) by it, then an expiation for zihar becomes obligatory upon you if you have intercourse with her. If he intends merely an oath or intends nothing specific, then an expiation for a broken oath becomes obligatory upon you. There is no consequence in repeating the statement unless he intends to initiate a new oath.