Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates this statement of the Prophet (peace and blessings be upon him): "Whoever combines Hajj and Umrah, he will perform one Tawaf for both of them, and he will not exit the state of Ihram until he has completed both."
Hadith Referenceصحیح ابن حبان / كتاب الحج / 3915
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - انظر ما بعده.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده ضعيف