1,490. "On the Condition That My Father Agrees"

Hilchos Ishus 6:18

Pursuant to the preceding halacha, if a man tells a woman that she is consecrated to him on the condition that she gives him 200 zuz, that she is divorced on the condition that she gives him 200 zuz, or that he gives her a courtyard as a gift on the condition that she gives him 200 zuz, the condition is valid. She is married, divorced, or acquires the property but she must give the man the 200 zuz. If she doesn’t give it to him, then she will not be married, divorced, or acquire the property. This is so even if the man didn’t state both the positive and negative ramifications of the condition and/or even if he performed the related action before stating the condition, such as he putting the kiddushin or the get in the woman’s hand or allowing her to take possession of the real estate, only after which he stated the condition. The reason the four rules of conditions need not be met in these cases is because once the condition is fulfilled, she is married, divorced or acquires the property retroactive to the time the action was performed, so it’s as if a condition had never been made at all.

Hilchos Ishus 7:1

Let's say that a man tells a woman, "You are consecrated to me on the condition that my father agrees." If his father agrees, then marriage is effected but if he doesn't agree, if he remains silent, or if he dies before hearing about the condition, then marriage is not effected (because he never agreed). Let's say the man says, "You are consecrated to me on the condition that my father doesn't object." If the father hears and objects, marriage is not effected. If he doesn't object or if he dies, marriage is effected. If the son dies and the father later hears about the condition, he is instructed to say, "I object" so that marriage won't be effected and the woman won't have to undergo yibum (levirate marriage).