Sahih Bukhari Volume 008, Book 076, Hadith Number 501.

Narated By Abu Sa'id Al-Khudri : A Bedouin came to the Prophet and said, "O Allah's Apostle! Who is the best of mankind!" The Prophet said, "A man who strives for Allah's Cause with his life and property, and also a man who lives (all alone) in a mountain path among the mountain paths to worship his Lord and save the people from his evil."