Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrated that the Messenger of Allah (peace and blessings be upon him) said: "There are no days in which deeds are more beloved to Allah, the Mighty and Majestic, (or he said: more excellent) than these ten days." It was said: O Messenger of Allah, not even jihad? He said: "Not even jihad, except for a man who goes out with his life and his wealth and brings nothing of that back."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12274