Ibn 'Abbas (May Allah be pleased with them) reported:
The Messenger of Allah ﷺ said, "There are no days during which the righteous action is so pleasing to Allah than these days (i.e., the first ten days of Dhul-Hijjah)." He was asked: "O Messenger of Allah, not even Jihad in the Cause of Allah?" He ﷺ replied, "Not even Jihad in the Cause of Allah, except in case one goes forth with his life and his property and does not return with either of it."

[Al-Bukhari].

وعن ابن عباس رضي الله عنهما قال: قال رسول الله ﷺ: " ما من أيام العمل الصالح فيها أحب إلى الله من هذه الأيام" يعني أيام العشر، قالوا: يا رسول الله ولا الجهاد في سبيل الله؟ قال: "ولا الجهاد في سبيل الله، إلا رجل خرج بنفسه، وماله فلم يرجع من ذلك بشيء" ((رواه البخاري)).