Is the divorce oath of the husband who says, "If you do such and such, then you are divorced, and your father will send you your travel ticket," still valid after the father's death, and will a divorce occur if I do that?

The majority of scholars hold that if a husband makes his wife's divorce conditional upon an event, the divorce occurs when that condition is met, regardless of whether the husband intended to effect a divorce or merely to threaten, emphasize, or prevent. This is the fatwa (definition) we adopt. Some scholars, like Sheikh al-Islam Ibn Taymiyyah - may Allah have mercy on him - are of the view that if the husband did not intend to effect a divorce, but rather intended to threaten, emphasize, or prevent, then divorce does not occur when the condition is met; rather, he is obligated to offer an expiation for breaking an oath (kaffarat yamin (definition)). Accordingly, the fatwa we adopt is that if you do what your husband forbade you from doing, your divorce will occur. Your father's death has no effect on this oath, so the oath will not be dissolved except by your husband breaking it and divorce occurring.