פּירוש אויף אסתר 3:6

And in his being so highly elevated, in that he was second to the king, it was disgraceful in his eyes to lay hands on Mordekhai alone, to take revenge against the one who disgraced him. But since they told him that Mordekhai’s people were the enemies of his people from way back and from before, and there was war towards them from generation to generation, such that fury was added to anger, he sought to destroy all the Jews, etc. As it was easy in his eyes to annihilate them, since they were all beneath Ahasuerus, his friend. And that is because they were Jews and the enemies of his people. And since they were Mordekhai’s people, as he was their minister and officer then, and he was the one who sinned against him privately when he disgraced him.