The Prophet 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 Rakat 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 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 offered two more
Rakat 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.