Is it permissible for a woman to remain with her husband after she lied under oath to avoid being forbidden to him, knowing that four months have passed since the incident?

A husband's declaration of حرمة (prohibition) upon his wife can be a divorce, a ẓihār, or a redeemable oath, depending on his intention. If a man says to his wife, "If you said such and such, you become forbidden to me," it is necessary to refer back to him to ascertain his intention. If the wife lies and claims she did not say it, then what the husband intended takes effect. If a divorce occurred and she was not taken back during her iddah (waiting period), she becomes irrevocably separated, and her remaining with him and his sexual intimacy with her are forbidden. If ẓihār occurred, sexual intimacy with her is forbidden until he performs expiation (kaffārah), and the sin for each act of intimacy falls upon the wife. If it was an oath, he must perform an expiation for the oath, and sexual intimacy with her is not forbidden before the expiation. The wife must inform her husband of her lie so that the ruling becomes clear, unless she fears great harm. In that case, she should ask him about his intention. If he did not intend divorce or ẓihār, she should remain silent, and an expiation for an oath is due from her. She can then ask his permission later to perform the expiation on his behalf. However, if he intended divorce or ẓihār, she must inform him.