פירוש על אסתר 10:4

By most of his brethren. By not by all his brethren, this teaches us that part of the Sanhedrin separated from him because he became close to the monarchy and neglected his studies.¹Maseches Megillah 16b and see Rashi there.

Of all his descendants. This refers back to “of his people,” i.e., to all the seed of his people.