Bayhaqi 3892 — How to perform the prostration of forgetfulness

Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) led us in one of the prayers after the sun's decline (Zuhr or Asr). The narrator says: My strongest belief is that he said Zuhr. He (peace and blessings be upon him) gave the salam after leading us in two rak'ahs, then he (peace and blessings be upon him) went to a piece of wood set up in front of the place of prostration and stood with his hand placed on it. Signs of anger were evident on his (peace and blessings be upon him) blessed face. Then the people who hurry out left, saying: "Has the prayer been shortened? Has the prayer been shortened?" Among the people present were Sayyiduna Abu Bakr and Sayyiduna Umar (may Allah be pleased with them both), but they too were too awed to speak in front of him (peace and blessings be upon him). Among the people was a man whom the Messenger of Allah (peace and blessings be upon him) used to call Dhu al-Yadayn. He said: O Messenger of Allah, have you forgotten, or has the prayer been shortened? He (peace and blessings be upon him) said: "I have neither forgotten, nor has the prayer been shortened." He said: Then you have forgotten. He (peace and blessings be upon him) said: "Dhu al-Yadayn has spoken the truth." Then the Messenger of Allah (peace and blessings be upon him) led the remaining two rak'ahs, gave the salam, said the takbir and prostrated like his usual prostrations or somewhat longer, then raised his head, and said the takbir and prostrated, then said the takbir and raised his head.
(b) In one narration the wording is: "And my strongest belief is that it was Asr."