Rabbi Eliezer said: He called the name of Phineas by the name of Elijah—Elijah of blessed memory, (who was) of those who repented in Gilead, for he brought about the repentance of Israel in the land of Gilead. The Holy One, blessed be He, gave him the life of this world and the life of the world to come, as it is said, "My covenant was with him of life and peace" (Mal. 2:5). He gave to him and to his sons a good reward, in order that (he might have) the everlasting priesthood, as it is said, "And it shall be unto him, and to his seed after him, the covenant of an everlasting priesthood" (Num. 25:13).
Kingdom of Phineas
Pirkei DeRabbi Eliezer 47:8