From Sahih Bukhari (Hadith 7249):
Narrated `Abdullah:The Prophet (ﷺ) led us in Zuhr prayer and prayer five rak`at. Somebody asked him whether the prayer had been increased." He (the Prophet (ﷺ) ) said, "And what is that?" They (the people) replied, "You have prayed five rak`at." Then the Prophet (ﷺ) offered two prostrations (of Sahu) after he had finished his prayer with the Taslim
Reference: Bukhari 7249