And the evidence for the error of those who claim that if someone gives salam after the third unit out of forgetfulness and then speaks while not remembering that some of his prayer remains, that he must repeat the prayer, is that this statement is contrary to the Sunnah of the Prophet, peace and blessings be upon him.

Sayyiduna Imran bin Husain (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings of Allah be upon him) ended the prayer after the third rak‘ah of ‘Asr, then he stood up and went into the blessed chamber. Then Khirbaq, a man with long arms, called out to him and said,“O Messenger of Allah, has the prayer been shortened?”So the Messenger of Allah (peace and blessings of Allah be upon him) came out angrily, dragging his cloak, and inquired about the matter. He was informed (that one rak‘ah had been left). The Messenger of Allah (peace and blessings of Allah be upon him) performed the missed rak‘ah, then performed two prostrations, then gave salam. These are the words of Bundar’s narration—while other narrators have reported the words: then he gave salam, then performed two prostrations, then gave salam.