What is the ruling on saying, “I swear by divorce that you will do such-and-such”? Is this shirk (associating partners with Allah) and an oath by other than Allah?

Question:
He says: Honorable Shaykh, may Allah grant you success. What is the ruling on some people saying, “I swear by divorce that you will do such-and-such”? Is this shirk (associating partners with Allah) and an oath by other than Allah?

Answer:
No, this is in the nature of an oath, though it is not actually an oath. However, it is treated as an oath because the matter is conditioned upon its performance or its abandonment. Thus, it is in the nature of an oath, but it is not an oath. An oath is what is made with the letter waw, or ba, or ta, such as “By Allah,” “I swear by Allah,” or “By Allah.”