The Condition of the Guardian Having the Woman’s Consent Before Marrying Her for the Nikaah to be Valid:
The Messenger of Allaah (sallallaahu `alaihi wa sallam) said:
“The Thayyib* must not be married until she is consulted and the virgin must (also) not be married her permission is sought.” They said:
“O Messenger of Allaah! How will she (the virgin) express her consent (i.e. if she is shy)?” He replied:
“By keeping silent.”
*Thayyib: not virgin, widow or divorced.
Reported by Al-Bukhaaree (5136) and Muslim (3458).