e read in Parashat Matot of the war that G-d commanded Beneh Yisrael to wage against the nation of Midyan to avenge the tragedy of Ba'al Pe'or. Midyan, together Moav, conspired to lure Beneh Yisrael to sins of immorality and idol-worship. The scheme, unfortunately, succeeded, and G-d punished Beneh Yisrael by sending a plague that killed 24,000 members of the nation. Hashem instructed Beneh Yisrael to wage war against Midyan in order to take revenge. The Torah relates that this battle was led by Pinhas, the son of the Kohen Gadol, Elazar (31:6). Rashi gives two reasons for why specifically Pinhas was chosen to lead the war. First, he was the one who saved Beneh Yisrael from annihilation during the calamity of Ba'al Pe'or, by killing a man and woman who committed a public sinful act. Once Pinhas avenged G-d's honor, G-d ended the plague. Rashi writes that since Pinhas began the Misva by killing these two violators, he was chosen to complete the Misva by leading the war against Midyan. But then Rashi adds a second explanation. He writes that Pinhas led the war against Midyan to avenge that nation's role in the sale of his ancestor, Yosef, as a slave. Pinhas' mother was a descendant of Yosef, and merchants from Midyan were the ones who, after purchasing Yosef from his brothers, brought him to Egypt and sold him to Potifar, an Egyptian nobleman. It was thus appropriate for Yosef's descendant, Pinhas, to lead Beneh Yisrael's war against the people of Midyan. Rashi's comments seem puzzling. Why should Midyan be blamed for Mechirat Yosef (the sale of Yosef as a slave)? It was Yosef's brothers who turned on him; the Midyanim simply accepted the offer and paid for Yosef, after which they sold him for a profit. Why did their role in Mechirat Yosef need to be avenged? Yosef excelled particularly in the area of Kedusha, maintaining his sanctity and purity even in the face of overwhelming temptation. As a teenager, he was lured to sin by Potifar's wife, and he resisted. The Midyanim, it appeared, had sinister intentions when they brought Yosef to Egypt, a society which at that time was steeped in decadence and immorality. They wanted to ruin Yosef by compromising his Kedusha, by putting him in a place where – they incorrectly assumed – he would be unable to withstand temptation and would be lured to sin. This is precisely what Midyan did several generations later, at Ba'al Pe'or. They tried destroying Beneh Yisrael by luring them to immorality, which would undermine their spirituality. Appropriately, then, Pinhas – a descendant of Yosef – led the war against Midyan, because this war avenged Midyan's devious scheme both at Ba'al Pe'or and with Mechirat Yosef. Our nation's struggle against Midyan continues to this very day, with greater intensity than ever. Contemporary society champions values that directly oppose the Torah's values of Kedusha and purity, and we are exposed at all times to lures that threaten to divest us of our sanctity. Hashem commanded Beneh Yisrael to wage war against Midyan – because we need to proactively reject and oppose the efforts made to undermine our Kedusha. We must continue waging this vitally important battle that began with Yosef and then proceeded with Pinhas, and work to oppose the sinful influences and lures that we face on a daily basis.