Hadith 9:67
Hafs narrated to us, from Ibn Jurayj, from ‘Ata’, who said: When the Messenger of Allah (peace and blessings of Allah be upon him) would propose on behalf of one of his daughters, he would sit beside her curtain and say: "So-and-so is proposing to so-and-so." If she remained silent, he would marry her off. But if she struck with her hand—and Hafs gestured with his index finger, meaning she strikes the curtain—he would not marry her off.
حدثنا حفص عن بن جريج عن عطاء قال كان رسول الله صلى الله عليه وسلم إذا خطب أحدا من بناته جلس إلى جنب خدرها فقال إن فلانا يخطب فلانة فإن سكتت زوجها وإن طعنت بيدها وأشار حفص بيده السبابة أي تطعن في الخدر لم يزوجها