It was narrated from Ibn 'Abbas that

The Prophet (ﷺ) said: "There are no days on which righteous deeds are more beloved to Allah than these days," meaning the first ten days of Dhul-Hijjah. It was said: not even jihad for the sake of Allah? He said, “Not even jihad for the sake of Allah, unless a man goes out with himself and his wealth and does not come back with any of that.”