Hazrat Ibn Abbas, Allah be pleased with him, narrates that the Holy Prophet, peace and blessings of Allah be upon him, said:
“There are no days during which righteous deeds are more beloved to Allah than these days,” meaning the [first] ten days of Dhul-Hijjah. They said: “O Messenger of Allah! Not even Jihad in the cause of Allah?” He said: “Not even Jihad in the cause of Allah, unless a man goes out by himself and his wealth and does not bring anything back.”
(Sunan Ibn Majah)