Lady Aisha Siddiqa (may Allah be pleased with her) narrates: When the Prophet Muhammad (peace and blessings be upon him) performed nine rak‘ahs of Witr, he would only sit after the eighth rak‘ah. Then he would praise Allah Almighty, mention Him, and supplicate to Him. Then he would stand up without saying salam, perform the ninth rak‘ah, mention Allah Almighty, and supplicate to Him. Then he would say salam aloud. After that, he would sit and perform two rak‘ahs.
Hadith Referenceصحیح ابن حبان / كتاب الصلاة / 2442
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح: م - انظر ما قبله.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناد صحيح على شرط الشيخين.