Does divorce take effect if the husband says to his wife: "By Allah's will, the day of your cousin's wedding will be the day of your divorce," and her cousin's wedding is in five days?

Suspending a divorce on the marriage of the wife's cousin is considered a pure suspension by which divorce occurs when the condition is met.

As for adding "in shaa Allah (God willing)", if the intention is to suspend the divorce on God's will, then there is a difference of opinion among scholars regarding its occurrence. It was narrated from Ibn Qudamah that Ahmad said it occurs, while others held that it does not. However, if "in shaa Allah" was intended for emphasis, seeking blessings, or it was uttered habitually without the intention of suspension, then the divorce occurs.

Ibn Uthaymeen points out that the middle ground is that divorce occurs if the husband intends that God wills its occurrence with this statement, and it does not occur except in the future if that is his intention. If he intends seeking blessings and not suspension, then the divorce occurs.

Al-Shanqeeti adds that the disagreement regarding "in shaa Allah" arises when the intention is to suspend. However, if it is said for seeking blessings, or it is uttered habitually without the intention of suspension, or if it is intended to confirm and establish the matter, then the divorce occurs unequivocally. The husband must fear God and not use divorce except in its proper place.