Sha'ar Ha'Gemul of the Ramban
שער הגמול - רמב''ן
Sefaria Community Translation
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Sha'ar Ha'Gemul of the Ramban

...Our rabbis taught (Rosh Hashanah 16b): "Three books are opened on Rosh Hashanah - one for thoroughly righteous people, one for thoroughly evil people, and one for the average people. Thoroughly righteous people are inscribed and sealed immediately for life; thoroughly evil people are inscribed and sealed immediately for death; average people remain undetermined for between Rosh Hashanah and Yom Kippur. If they merit it, they are inscribed for life; if they do not merit it, they are inscribed for death." That which the sages said of righteous people -  that they are inscribed for life - or evil people - that they are inscribed for death - is not said of righteous people who have no sins or evil people who have no merits, for many righteous people die immediately, and many evil people live long lives in serenity. Also, the verse (Ecclesiastes 8) cries out "that there are righteous people whose experiences [would be fitting recompense for] the actions of evil people, and evil people whose experiences [would be fitting recompense for] the actions of righteous people." Already, Sages have said (Pirkei Avot 4) that "it is within our grasp [to understand] neither the tranquility of the wicked nor the suffering of the righteous." Rather, this is the rule: There are sins that - as determined by The Holy One, Blessed is He and His just laws - are requited for in this world, and there are some in which the law is that they will be requited for in the world to come. So also for merits - there are some of them for which the Master of Reward pays their wages in this world, and some in the world to come. When a man sins constantly and begrimes himself with iniquities and besmirches himself with sins and rolls around in his wanton violations, but also does acts of charity and good deeds - when his actions come before the Master of All, He weighs these actions against those. The righteous person who is thoroughly righteous achieves life, and similarly the evil person - whose verdict it is that he will be paid his reward in this world for his good actions - is also inscribed and sealed immediately on Rosh Hashana for life. That is to say, that he [the evil man] is awarded life, serenity, wealth, possessions, and honor.