The Prophet ﷺ prayed Dhuhr as five rakahs. He was asked, "Has the prayer been increased?"He replied, "Why do you ask?"They informed him of what had happened, so he turned his leg and performed two prostrations.
حدثنا محمد بن بشار وأبو بكر بن خلاد قالا حدثنا يحيى بن سعيد عن شعبة حدثني الحكم عن إبراهيم عن علقمة
صلى النبي ﷺ الظهر خمسا فقيل له أزيد في الصلاة قال وما ذاك فقيل له فثنى رجله فسجد سجدتين
Bukhari related it in the Book of Prayer, Chapter on what has been said regarding qibla and whoever does not think the prayer should be repeated, etc., hadith no. 404, from the hadith of Yahya. Muslim related it in the Book of Mosques, Chapter on forgetfulness in prayer and the sujud for it, hadith no. 572, from the hadith of Shubah, through him.