Narrated Ibn Abbas (ra) :
The Prophet (saw) said, “No good deed done on other days is superior than what is done on these (first ten days of Dhul-Hijjah).” Then some companions of the Prophet said, “Not even Jihad?”
He (saw) replied, “Not even Jihad, except in the case of a man who goes out with his life and wealth in danger and returns with nothing.”
Source: [Sahih Bukhari, Volume 2, Book 15, Number 86]