Hadis Bukhari

Narrated Anas bin Malik:
The Prophet said, "Nobody who dies and finds good from Allah (in the Hereafter) would wish to come back to this world even if he were given the whole world and whatever is in it, except the martyr. Who, on seeing the superiority of martyrdom, would like to come back to the world and get killed again (in Allah's Cause)."
Narrated Anas: The Prophet said, "A single endeavor (of fighting) in Allah's Cause in the afternoon or in the forenoon is better than all the world and whatever is in it. A place in Paradise as small as the bow or lash of one of you is better than all the world and whatever is in it. And if a houri from Paradise appeared to the people of the earth, she would fill the space between Heaven and the Earth with light and pleasant scent and her head cover is better than the world and whatever is in it."

Sahih Bukhari hadis 2610

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A man whose face was covered with an iron mask (i.e. clad in armor) came to the Prophet and said, "O Allah's Apostle! Shall I fight or embrace Islam first? "The Prophet said, "Embrace Islam first and then fight." So he embraced Islam, and was martyred. Allah's Apostle said, A Little work, but a great reward. "(He did very little (after embracing Islam), but he will be rewarded in abundance)."

Sahih Bukhari hadis 2620