From Sahih Bukhari (Hadith 830):
Narrated `Abdullah bin Malik bin Buhaina:Once Allah's Messenger (ﷺ) led us in the Zuhr prayer and got up (after the prostrations of the second rak`a) although he should have sat (for the Tashahhud). So at the end of the prayer, he prostrated twice while sitting (prostrations of Sahu)
Reference: Bukhari 830