Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrated that the Prophet (peace and blessings be upon him) said: "There are no days in which deeds are more excellent than in the ten days of Dhu al-Hijjah." The Companions said: O Messenger of Allah, not even jihad in the path of Allah? He said: "Not even jihad in the path of Allah, except that a man goes out with his life and his wealth and then brings nothing of that back."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12275