It has been narrated on the authority of Abu Hurairah (RA) that the Messenger of Allah (ﷺ) said: God laughs at the two men both of whom will enter Paradise (though) one of them kills the other. They said: Messenger of Allah, how is it? He said: One of them fights in the way of Allah, the Almighty and Exalted. and dies a martyr. Then God turns in mercy to the murderer who embraces Islam, fights in the way of Allah, the Almighty and Exalted, and dies a martyr.
It has been reported on the authority of Abu Hurairah (RA) that the Messenger of Allah (ﷺ) said: God laughs at the two men one of whom kills the other; both of them will enter Paradise. They (the Companions) said: How, Messenger of Allah? (ﷺ) He said: One is slain (in the way of Allah) and enters Paradise. Then God forgives the other and guides him to Islam; then he fights in the way of Allah and dies a martyr.