Parshat Pinchas פרשת פנחס with thanks to Dr. David Bernat (thetorah.com)

(11) “Pinchas, son of Elazar son of Aaron the priest, has turned back My wrath [extreme anger] from the Israelites by displaying among them his passion for Me, so that I did not wipe out the Israelite people in My passion. (12) Say, therefore, ‘I grant him My pact of peace. (13) It shall be for him and his descendants after him a pact of priesthood for all time, because he took impassioned action for his God, thus [or "and also"] making forgiveness for the Israelites.’” (14) The name of the Israelite man who was killed, the one who was killed with the Midianite woman, was Zimri son of Salu, chieftain of a Simeonite ancestral house. (15) The name of the Midianite woman who was killed was Cozbi daughter of Zur; he was the tribal head of an ancestral house in Midian.

(28) They attached themselves to Baal Peor,
ate sacrifices offered to the dead. (29) They provoked anger by their deeds,
and a plague broke out among them. (30) Pinchas stepped forth and intervened/judged,
and the plague ceased. (31) It was reckoned [considered] to his merit
for all generations, to eternity.

(6) With regard to one who steals a kasva [a vessel used in the Temple], and one who curses with a sorcerer [like a wizard], and one who engages in intercourse with an Aramean woman, zealots strike him and kill him. Although the Torah does not say that one who performs one of these actions is liable to be executed, it is permitted for anyone who zealously takes the vengeance of the Lord to do so. In the case of a priest who performed the Temple service in a state of ritual impurity, his priestly brethren [brothers] do not bring him to court for judgment; rather, the young men of the priesthood remove him from the Temple courtyard and pierce his skull with pieces of wood. In the case of a non-priest who performed the service in the Temple, Rabbi Akiva says: His execution is by strangulation, and the Rabbis say: He is not executed with a court-imposed death penalty; rather, he is liable to receive death at the hand of Heaven.

The Gemara asks: What did Pinchas see that led him to arise and take action? Rav says: He saw the incident taking place before him and he remembered the halakha [Jewish law]. He said to Moses: Brother of the father of my father, as Moses was the brother of his grandfather Aaron, did you not teach me this during your descent from Mount Sinai: One who engages in intercourse with a gentile woman, zealots strike him? Moses said to him: Let the one who reads the letter be the agent [parvanka] to fulfill its contents.

(2) In cases of monetary law [financial law], and likewise in the cases of ritual impurity and purity, the judges commence expressing their opinions from the greatest of the judges. In cases of capital law [death penalty law], the judges commence issuing their opinions from the side, where the least significant judges sit. All are fit to judge cases of monetary law. But not all are fit to judge cases of capital law; only priests, Levites, and Israelites who are of sufficiently fit lineage [Jewish legal background] to marry their daughters to members of the priesthood are fit to judge cases of capital law.

Rav Chisda says: Concerning one who comes to consult with the court when he sees a Jewish man engaging in intercourse with a gentile woman, the court does not instruct him that it is permitted to kill the transgressor. It was also stated that Rabba bar bar Chana says that Rabbi Yoḥanan says: Concerning one who comes to consult with the court, the court does not instruct him that it is permitted to kill the Jewish man engaging in intercourse with a gentile woman. Moreover, if Zimri son of Salu (see Numbers 25:1–9) had separated himself from the woman and only then Pinchas killed him, Pinchas would have been executed for killing him, because it is permitted for zealots to kill only while the transgressor is engaged in the act of intercourse. Furthermore, if Zimri would have turned and killed Pinchas in self-defense, he would not have been executed for killing him, as Pinchas was a pursuer. One is allowed to kill a pursuer in self-defense, provided that the pursued is not liable to be executed by the court.

“One who copulates [sleeps with] with a Gentile woman,” etc. Rebbi Ismael stated: This is one who marries a Gentile woman, sires [has] children, and from her raises enemies of the Omnipresent [God]. It is written: Pinchas ben Eleazar ben Aharon the priest saw. What did he see Since Zimri did his deed in public, everybody saw? He understood what happened and remembered practice: “One who copulates with a Gentile woman, zealots strike him.” It was stated: not with the agreement of the Sages. Would Pinchas act against the Sages? Rebbi Yehudah bar Pazi said, they wanted to excommunicate him [kick him out of the community] had not the Holy Spirit jumped on him and declared that an eternal covenant of priesthood shall be for him and his descendants after him.

(5) "And it shall be unto him and to his seed after him a covenant of eternal priesthood": This refers to the twenty-four priestly gifts bestowed upon [given to] the Cohanim. (Ibid.) "because he was wrath for his G-d": because he was ready to give his life. (Ibid.) "and he will atone for the children of Israel": It is not written "to atone for the children of Israel," but "and he will atone for the children of Israel." Until now he has not stirred (from his place), but he stands and atones until the revival of the dead.