What is the ruling when the wife attempts to condition her expressed will on another factor?

Primary text

If the husband states, 'You are divorced if you wish,' and the wife responds by saying, 'I have willed it if my father wills,' and then the father wills, the divorce does not occur because the wife herself did not truly express a definitive will. The expression of will ('mashi'a') is an intrinsic, hidden matter, and conditioning it upon a contingent term is invalid. Similarly, if she says, 'I have willed it if you wish,' and the husband says, 'I have willed it,' or if she says, 'I have willed it if the sun rises,' the divorce is not established. Ahmad expressed this meaning, which is the position of the majority of scholars.