It is not written here (Psalms 121:1) "a song of the ascents," but "a song to the ascents" — to Him who is destined to assign ascents to the righteous in time to come. Rebbi says: It is not written here "a song of the ascents," but "a song to the ascents" — thirty ascents, one above the other. Because there are (thirty) ascents, one higher than the other, I might think that there is hatred, envy, and rivalry among them; it is, therefore, written (Daniel 12:3) "and they that turn the many to righteousness (will shine) as the stars forever."
Just as there is no hatred, envy, or rivalry among the stars, so, there will be no hatred, envy, or rivalry among the righteous. And just as with the stars, the light of one is not like the light of the other, so, with the righteous. Variantly: (Ibid.) "and the wise ones will shine as the brightness of the firmament": This is a judge who renders a judgment in accordance with the pure truth.