Anas told that ar-Rubaiyi‘ daughter of al-Bara’, who was the mother of Haritha b. Suraqa, came to the Prophet and said, “Prophet of God, will you not tell me about Haritha? (He had been killed at the battle of Badr, being struck by a random arrow.) If he is in paradise I shall show endurance, but if he has met another fate I shall exert myself in weeping for him.” He replied, “Mother of Haritha, in paradise there are gardens, and your son has attained to al-Firdaus, the highest.”
Sahl b. Hunaif reported God’s Messenger as saying, “If anyone asks God for martyrdom with a genuine purpose God will bring him to the dwellings of the martyrs, even if he dies on his bed.”
He told that God’s Messenger and his companions went off and reached Badr before the polytheists, and when the polytheists arrived he said, “Rise to go to a garden whose breadth is as great as the heavens and the earth.” ‘Umair b. al-Humam thereupon said, “Bravo, bravo!” and when God’s Messenger asked him what had made him say that, he replied, “Nothing, I swear by God, Messenger of God, but a hope that I might be among its inhabitants.” He told him that he would be among them. He then took some dates out of his quiver and began to eat them, but after a little said, “If I live till I eat my dates it will mean a long life.” So he threw away the dates he had and then fought with the enemy till he was killed.
Abu Huraira reported God's Messenger as saying, "God most high will cheerfully welcome two men one of whom kills the other. They will enter paradise, one having fought in God’s path and been killed, and the slayer, after receiving God's pardon, having died as a martyr."*
* The man who had fought and killed a Muslim later became a Muslim himself and was killed in the course of jihad.