Sahih al-Bukhari 1228

The Prophet (ﷺ) led us in the `Asr or the Zuhr prayer and finished it with Taslim. Dhul-Yadain said to him, "O Allah's Messenger (ﷺ)! Has the prayer been reduced?" The Prophet (ﷺ) asked his companions in the affirmative. So Allah's Messenger (ﷺ) offered two more rak`at and then performed two prostrations (of Sahu). Sa`d said, "I saw that 'Urwa bin Az-Zubair had offered two rak`at in the Maghrib prayer and finished it with Taslim. He then talked (and when he was informed about it) he completed the rest of his prayer and performed two prostrations, and said, 'The Prophet (ﷺ) prayed like this

The Prophet (ﷺ) offered one of the evening prayers (the sub-narrator Muhammad said, "I think that it was most probably the `Asr prayer") and he finished it after offering two rak`at only. He then stood near a piece of wood in front of the Mosque and put his hand over it. Abu Bakr and `Umar were amongst those who were present, but they dared not talk to him about that (because of excessive respect for him), and those who were in a hurry went out. They said, "Has the prayer been reduced?" A man who was called Dhul-Yadain by the Prophet (ﷺ) said (to the Prophet), "Has the prayer been reduced or have you forgotten?" He said, "Neither have I forgotten, nor has the prayer been reduced." He said, "Certainly you have forgotten." So the Prophet (ﷺ) offered two more rak`at and performed Taslim and then said Takbir and performed a prostration of Sahu like his ordinary prostration or a bit longer and then raised his head and said Takbir and then put his head down and performed a prostration like his ordinary prostration or a bit longer, and then raised his head and said Takbir