Sahih Bukhari
Sahih Bukhari Volume 004, Book 052, Hadith Number 321.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 52. Fighting for the Cause of Allah (Jihaad)
Narated By Ka'b : Whenever the Prophet returned from a journey in the forenoon, he would enter the Mosque and offer two Rakat before sitting.