זו מחלוקת הלל ושמאי. לפי שתלמידיהם לא שמשו כל צרכן ומהם ואילך רבתה המחלוקת בישראל לפיכך נקטינהו לדוגמא. ומש"ה נמי לא קשיא רישא לסיפא: THE DISPUTE OF HILLEL AND SHAMMAI. Their students did not fully absorb their ways and teachings, and from that point on disputes became more common among the Torah scholars. This is why the mishna chooses their dispute as an example. Accordingly, the beginning of the mishna does not contradict the end.232Just as in the previous mishna, it would seem that any dispute that is not on the same level as a dispute between Hillel and Shammai is not “for the sake of Heaven”. The end of the mishna, however, makes it clear that only a dispute like that of Korach and his followers is considered “not for the sake of Heaven.” Tosafot Yom Tov clarifies that the dispute of Hillel and Shammai is merely an example, and other disputes that are for the sake of truth and not for personal gain would likewise be called “for the sake of Heaven.”
זו מחלוקת קרח וכל עדתו. לא הזכיר צד השני של מחלוקת שהם משה ואהרן כמו שזכר בחלוקה ראשונה ב' הצדדים לפי שבכאן אינם שוים שמשה ואהרן כוונתם לשמים היתה. ולא היתה בהם שום בחינה שלא לש"ש. מד"ש בשם הר"י לירמא: THE DISPUTE OF KORACH AND HIS FOLLOWERS. The mishna does not mention the other party in the dispute—Moses and Aaron—as it does in the first section because in this case the two parties are not comparable, for Moses and Aaron acted for the sake of Heaven and had no other motives at all—Midrash Shmuel in the name of R. Yehuda Lerma.