Sahih Bukhari Volume 8, Book 76, Hadith Number 473.

Narated By ‘Alqama : I asked ‘Aisha, mother of the believers, “O mother of the believers! How were the deeds of the Prophet? Did he use to do extra deeds of worship on special days?” She said, “No, but his deeds were regular and constant, and who among you is able to do what the Prophet was able to do (i.e. in worshipping Allah)?”