"...the one in whose hand is the marriage contract." Shurayh said: It is the husband; if he wills, he may forgo the half of the dower, and thus give the woman the full dower. And if the woman wills, she may forgo the half of the dower, and thus surrender the entire dower to the husband.
Yahya: Al-Hasan used to say: The one in whose hand is the marriage contract is the guardian. "And to forgo is nearer to righteousness," meaning that doing so is part of righteousness. "And do not forget the grace between you," meaning: do not abandon it. [Ayah 238-239]