Does the deferred dowry (three kilograms of gold) remain an obligation upon the husband's estate after his death, and is it permissible for the spouses to change this deferred amount by agreement after the marriage contract?

The deferred dower (mu'akhkhar as-sadaq) is a debt owed by the husband, which becomes due upon divorce or death. It is not permissible for the husband to coerce his wife into waiving it. Her waiver under duress does not make it permissible for him, for the Prophet, peace and blessings be upon him, said: "The property of a Muslim person is not lawful unless given with their willing consent."

The husband may ask his wife to waive it without coercion. If she agrees, and she is an adult, sane, and of sound judgment, then this is permissible and valid. However, if the wife requests to retract her waiver, which was made at the husband's request, she is permitted to do so, due to the possibility of her fearing harm. But if she waived it of her own accord, she is not permitted to retract it.

It is not permissible to declare the wife forbidden if she does not waive the deferred dower. If she waives it under such pressure, it is not permissible for the husband to take it. If she waives it of her own free will, it is permissible for him to take it. However, if she does not waive it, then the oath (of declaring her forbidden) has been broken. The ruling on a man's statement to his wife, "If you do not do such-and-such, then you are forbidden to me," depends on his intention (divorce, dhihar, or an oath).