Sahih Muslim
The Book of Prayers (Kitab Al-Salat)
Book Number: 004 / Hadith Number: 1712
Alqama reported: I asked 'A'isha, the mother of the believers, saying O mother of the believers, how did the Messenger of Allah (may peace be upon him) act? Did he choose a particular act for a particular day? She said: No. He act was continuous, and who amongst you is capable of doing what the Messenger of Allah (may peace be upon him) did?