It is narrated from Sayyiduna Umar (may Allah be pleased with him) that whenever the Messenger of Allah (peace and blessings be upon him) wished to marry off a woman under his care, he would come to her from behind the curtain and say: "O my daughter, so-and-so has proposed to you. If you dislike him, then say: No, for no one should feel shy to say no. And if you like him, then your silence is consent."
Hadith Referenceالمعجم الكبير للطبراني / العشرة / 87