Sahih Bukhari
Sahih Bukhari Volume 001, Book 010, Hadith Number 565.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 10. Times of the Prayers
Narated By Hisham's father : 'Aisha (addressing me) said, "O son of my sister! The Prophet never missed two prostrations (i.e. Rakat) after the 'Asr prayer in my house."