Sayyiduna Abdullah bin Buhaina (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) stood up after performing two rak‘ahs of the Zuhr prayer. He did not sit down. When he completed the prayer, he performed two prostrations of forgetfulness (sajda sahw), and then he gave salam.
Hadith Referenceصحیح ابن حبان / كتاب الصلاة / 2679
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح: ق - انظر ما قبله.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرطهما