The Prophet (ﷺ) prayed two rak`at of Zuhr prayer (instead of four) and he was told that he had prayed two rak`at only. Then he prayed two more rak`at and finished them with the Taslim followed by two prostrations.
Sahih al-Bukhari Book 10, Hadith 110
← Previous Hadith Once Allah's Messenger (ﷺ) prayed two rak`at (instead of four) and finished his prayer. Dhul-Yadain asked him whether the prayer had been reduced or whether he had forgotten. Allah's Messenger (ﷺ) asked the people whether Dhul-Yadain was telling the truth. The people replied in the affirmative. Then Allah's Apostle stood up, offered the remaining two rak`at and then finished his prayer with Taslim and then said, "Allahu Akbar." He followed it with two prostrations like ordinary prostrations or a bit longer.

Sahih al-Bukhari Book 10, Hadith 109 Next Hadith → the mother of the faithful believers: Allah's Messenger (ﷺ) in his last illness said, "Tell Abu Bakr to lead the people in the prayer." I said, "If Abu Bakr stood in your place, he would not be able to make the people hear him owing to his weeping. So please order `Umar to lead the prayer." He said, "Tell Abu Bakr to lead the people in the prayer." I said to Hafsa, "Say to him, 'Abu Bakr is a softhearted man and if he stood in your place he would not be able to make the people hear him owing to his weeping. So order `Umar to lead the people in the prayer.' " Hafsa did so but Allah's Messenger (ﷺ) said, "Keep quiet. Verily you are the companions of (Prophet) Joseph. Tell Abu Bakr to lead the people in the prayer." Hafsa said to me, "I never got any good from you."

Sahih al-Bukhari Book 10, Hadith 111