Sahih Bukhari, Chapter: Jihaad (Fighting for the cause of Allah)

Umm Ar-Rubai bint Al-Bara, the mother of Haritha bin Suraqa came to the Prophet (SAW) and said, "O Allah's Prophet (SAW)! Will you tell me about Haritha?" Haritha has been killed (i.e. martyred) on the day of Badr with an arrow thrown by an unidentified person. She added, "If he is in Paradise, I will be patient; otherwise, I will weep bitterly for him." He said, "O mother of Haritha! There are Gardens in Paradise and your son got the Firdaus Al-Ala (i.e. the best place in Paradise)."