From Sahih Muslim (Hadith 6358):
Abu Barza reported that Allah's Apostle (ﷺ) was there in a battlefield that Allah conferred upon him the spoils of war. He said to his Companions:Is anyone missing amongst you? They said: So and so and so. He again said: Is there anyone missing amongst you? They said: So and so and so. He then said: Is there anyone missing amongst you? They said: No. Thereupon he (the Holy Prophet) said: But I am missing Julaibib. They (his Companions) searched him amongst those who had been killed and they found him by the side of seven (dead bodies) whom he had killed and he had been killed (by the oppoments). Allah's Apostle (ﷺ) came there and stood (by his side) and said: He killed seven (persons). Then (his opponents) killed him. He is mine and I am his. He then placed him upon his hands and there was none else to lift but Allah's Apostle (ﷺ). Then the grave was dug for him and he was placed in the grave and no mention is made of a bath
Reference: Muslim 6358