Riyad as-Salihin: The Book of Jihad – Hadith No. 620 — Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah… (Hadith No. 620)

Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah (ﷺ) said, "The best life is that of the man who holds his horse's rein in Allah's way and flies on its back to the places from whence he hears a war cry or the clatter of arms, seeking martyrdom or slaughter on the battlefield; or that of a person who goes to stay on the top of the hill or in a valley, and there he performs Salat (prayer), pays the Zakat and worships his Rubb till death overtakes him. He has no concern with the affairs of anyone except the doing of good.".

Explanation:

Reference: Riyad as-Salihin, The Book of Jihad, Hadith No. 620