Musar for Yevamot 113:17

Let us now return to the four aspects of Torah which address themselves to four categories of the Jewish people. These are known as 1) עם, 2) קהל, 3) עדה, and 4) קהל השם. The first category which shares a certain level of intelligence includes the ערב רב, the mixed multitude of nations that became fellow travelers when the Jewish people left Egypt. By joining the Jewish people, they acquired a degree of holiness over and beyond their original intellectual capacity. The category of קהל is spiritually superior to that of עם. Our sages say that a community of proselytes, קהל גרים, is called a קהל, meaning that they are capable of understanding the commandments and their reasons (Yevamot 57a). עדה is a level superior to קהל, a level of people who are able to understand the meaning of His Holy Name, קהל ה', finally, is a reference to people whose soul is of such a level that it can re-unite with the original soul from which it had been parted.