“The ransom for a righteous man is a wicked man and in place of the upright people is the traitor” Mishlei 21:18 with the Vilna Gaon’s commentary!
The ransom for the righteous man is a wicked man – The righteous man and the upright I have previously explained what is the difference between them. And their opposite is the wicked man and the traitor.
A wicked man is the opposite of the righteous man, and a traitor is the opposite of the upright. And he said, “that the wicked man is “the ransom for the righteous man”, at the time that a decree is decreed against the righteous man for bad, the wicked man is his ransom, that the decree comes upon the wicked man and the righteous man does not know about his decree at all. Now on behalf of one righteous man, one wicked man will come as his ransom. And in place of the upright people is the traitor – that when it was already decreed that bad come against the upright people, then in the place of the many upright people, one traitor will serve as their ransom and they are redeemed from their decree. Since the upright are superior in comparison to the righteous, therefore even when a decree is directed against them, they only need one traitor to take their place.