Narrated 'Aisha: I asked the Prophet, "O Allah's Apostle! Should the women be asked for their consent to their marriage?" He said, "Yes." I said, "A virgin, if asked, feels shy and keeps quiet." He said, "Her silence means her consent."
— Sahih Bukhari, Volume 9, Book 85: Saying Something under Compulsion (Ikraah), Hadith #79