Musar zu Mischlej 13:9

This is like what our sages of blessed memory said regarding the light which G-d stored away for the righteous (Chagiga 12a): "when G-d saw the light which He stored away for the righteous, He rejoiced, as written: 'the light of the righteous rejoices' (Prov.13:9)".

We have to ask ourselves why these men were described as חטאים, whereas the Torah does not refer thus to the sons of Aaron. The answer is that they made common cause with Korach. Had they pursued their noble intentions without swelling the ranks of Korach and Datan and Aviram, they would not have been described as חוטאים, sinners at all. The Baal Haturim already alludes to this by quoting the number 250 as being the letters in the first word of Proverbs 13,9, ונר רשעים ידעך, that "the lamp of the wicked will be extinguished."