Fighting for the Cause of Allah (Jihaad)

Bukhari :: Book 4 :: Volume 52 :: Hadith 304

Narrated Jabir bin Abdullah:

I said, "O Allah's Apostle! We have slaughtered a young sheep of ours and have ground one Sa of barley. So, I invite you along with some persons." So, the Prophet said in a loud voice, "O the people of the Trench! Jabir had prepared "Sur" so come along."