Abu Dawud
Prayer
Book Number: 002 / Hadith Number: 1365
Narated By 'Alqamah : 'Aisha was asked about the actions of the Apostle of Allah (pbuh). Did he perform some actions exclusively on some particular days? She said: No, he performed his actions regularly. Which of you has the strength as much as the Apostle of Allah (pbuh) had?
Complete Translation of Sunan Abu-Dawud, Book 2: Prayer (Kitab Al-Salat): Detailed Injunctions about Ramadan