What is the ruling on saying "By the forbidden, I did not do such-and-such," and does this count as swearing by other than Allah?

Question:
He says: Honorable Shaykh, may Allah grant you success, when some people want to emphasize something, they say, "By the forbidden, I did not do such-and-such." What is their intention in saying this? And does it count as swearing by other than Allah?

Answer:
It is not permissible to say this. Saying "by the forbidden" may turn into zihar (likening one's wife to a forbidden relative) or may turn into talaq (divorce pronounced by the husband). It is not his intention to mean "the forbidden"; it may be zihar, or it may be talaq. Therefore, all of this is not permissible.