Numbers 25:13

It shall be. To him — this covenant of Mine.

A covenant of eternal kehunah. Although the kehunah had already been given to Aharon’s descendants, it was given solely to Aharon and his sons who were annointed with him, and to their generations who would be borne after their annointment. Pinchas, however, who was born before, and was not annointed, was not included in the kehunah until here. Similarly, we learned in Zevachim, ‘Pinchas was not rendered a kohein until he killed Zimri.’

For his God. For the sake of his God, like הַמְקַנֵּא אַתָּה לִי, “are you zealous ‘for’ me?” and קִנֵּאתִי לְצִיּוֹן, “for the sake of Tzion.”

And because they defamed him, saying, Is he not the son of Phuti, the Midianite? behold, I will make him to possess the high priesthood; and because he took the lance with his arm, and struck the Midianitess in her body, and prayed with his mouth for the people of the house of Israel, the priests shall be held worthy of the three gifts of the shoulder, the cheek-bone, and the inwards; and it shall be to him, and to his sons after him, an everlasting covenant of consecration, because he was zealous for the Lord, and propitiated for the children of Israel.

תחת אשר קנא לאלוקיו, seeing he had had the courage to fight My fight, I have ennobled him, granting him “peace” [a fitting reward for a noble fight. Ed.]

ויכפר על בני ישראל, seeing that he did what he did in full view of his peers so that they would obtain expiation for not having protested Zimri’s behaviour, he proved himself fit to become a priest whose primary function it is to secure expiation for the sins of their Jewish brethren. As a priest he could continue in the role he had first adopted on this occasion.

והיתה לו ולזרעו אחריו, “and both he and his descendants will enjoy the status of being priests.” This is the case with the descendants of all priests, but what is meant here is that the special priest assigned to soldiers before setting out on a war of conquest will always be one descended from Pinchas. (Compare both Numbers 31,6 and Talmud Zevachim, folio 101)It also follows that prior to Pinchas’ having killed Zimri in an act of zealousness he had not been a priest although he was the son of a priest.This also explains how Pinchas could have permitted himself to kill Zimri as by doing so he would defile himself, something forbidden for a priest to do? We would have been able to answer that up until now only Aaron himself and his sons had been forbidden to defile themselves through contact with a corpse.We find that also during the description of the consecration of Aaron and his sons as priests the Torah had emphasised the anointment of him and his sons, (not any grandsons. Compare Exodus 28,40-41.)It is also possible to answer that when Pinchas withdrew his dagger from Zimri and Cosbi, they had not yet been quite dead. [These speculations are necessary as there is a debate between the sages as to when Pinchas had become a priest. His priesthood might not have been hereditary to his descendants prior to here. Ed.] Concerning this interpretation, Rabbi Sh’muel raises the point that Pinchas must have been a priest in the full sense of the meaning of the word no later than on the eighth day of the consecrations rites, [38 years earlier. Ed.] or the Midrash could not have included him in the seven joyful events that Aaron’s wife Elisheva was supposed to have enjoyed on that day. It is possible that Moses appointed him to that position although he did not permit him to perform service in the Tabernacle until after he had earned that right by being zealous on G–d’s behalf at the right time at the right place. Only now had all the privileges of the priesthood been bestowed upon him and his descendants after him.

ויכפר על בני ישראל, “now that he had achieved atonement on behalf of the whole Jewish nation, he would henceforth be an instrument gaining atonement on other occasions.”