مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3115
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn ‘Abbas (رضي الله عنه) that The Prophet (ﷺ) said: "No deed is better than that done during these days," meaning the ten days (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, except for one who goes out with himself and his wealth and does not come back with either of them."
Musnad Ahmad 3139lts isnad is saheeh, al-Bukhari 1969)]