The Book of Prayers (Kitab Al-Salat)

Muslim :: Book 4 : Hadith 1178

'Abdullah (b. Mas'ud) reported: The Messenger of Allah (may peace be upon him) led us five (rak'ahs in prayer). We said: Messenger of Allah, has the prayer been extended? He said: What is the matter? They said: You have said five (rak'ahs). He (the Holy Prophet) said: Verily I am a human being like you. I remember as you remember and I forget just as you forget. He then performed two prostrations as (compensation of) forgetfulness.