Musannaf Ibn Abi Shayba 13:2228

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: ‘Amr ibn ‘Isa Abu Na’amah narrated to us, he heard it, and he said: Hujayr ibn al-Rabi’ al-‘Adawi narrated to us, he said: I heard ‘Umar ibn al-Khattab saying: I have prescribed for you three journeys: Hajj, ‘Umrah, and Jihad in the way of Allah. And a man striving with his wealth in any of these directions, seeking with my wealth the bounty of Allah, is more beloved to me than dying upon my bed. And if I were to say that it is martyrdom, I would consider it to be martyrdom.