Title: Kitaabun-Nikaah (The Book of Marriage) from Shaikh Saalih al-Fawzaan’s explanation of Buloogh al-Maraam min Adillatil-Ahkaam of Al-Haafidh Ahmad Ibn `Alee Ibn Hajr al-Asqalaanee (Born 773H, Died 852H). Shaikh Al-Fawzaan’s tremendous explanation is entitled Tas-heel al-Ilmaam bi-fiqhil-Ahaadeeth min Bulooghil-Maraam and is printed in seven volumes. The following is a translation of this important and very enlightening chapter, adapted in places for brevity and simplicity. The following is from volume 4.
Al-Haafidh Ibn Hajr (rahimahullaah) said:
984 (English print, no. 837): Narrated Abu Hurairah (radiyallaahu `anhu) that Allaah’s Messenger (salallaahu `alaihi wassallam) said:
“A previously married woman cannot be married off until she is consulted, and a virgin cannot be married off until she gives her consent.”
He was asked: “And how does she give consent?”
He replied: “By her silence.”
Reported by Bukhaaree and Muslim. 
 Bukhaaree, no. 5136, Muslim, no. 1419.
Shaikh Saalih al-Fawzaan (hafidhahullaah) said:
So this is proof of yet another condition for the validity of a marriage (nikaah) and that is one being pleased, and that a woman is married with her pleasure. If the woman is of the age of discernment, being able to distinguish between right and wrong, and she is sane, then seeking her permission is necessary regardless of whether she is a virgin or she was previously married. However the consent of the virgin differs from the consent of the one who was previously married. The previously married lady must give her verbal consent, whereas the silence of the virgin is sufficient. This is due to the latter’s shyness in speaking, unlike the previously married woman who is more bold because she has experienced marriage already. Nevertheless, as stated, the woman who has reached the age of being able to distinguish between what is beneficial and what is harmful, what is right from what is wrong, then her consent is a must.
This hadeeth is also a proof that a woman is not compelled or forced into marriage, regardless of whether she is a virgin or previously married. And those who make a difference between a virgin and a woman previously married by saying: “It is allowed to compel the virgin into marriage, but not a woman who has been previously married”, then this distinction is not correct and opposes the evidences.