The Talmud discusses the three books opened on Rosh Hashanah — the completely wicked, the completely righteous, and the intermediates (beinonim) — with the intermediates' judgment suspended until Yom Kippur, explaining the gap between initial judgment and final sealing.
אָמַר רַבִּי כְּרוּסְפָּדַאי אָמַר רַבִּי יוֹחָנָן: שְׁלֹשָׁה סְפָרִים נִפְתָּחִין בְּרֹאשׁ הַשָּׁנָה, אֶחָד שֶׁל רְשָׁעִים גְּמוּרִין, וְאֶחָד שֶׁל צַדִּיקִים גְּמוּרִין, וְאֶחָד שֶׁל בֵּינוֹנִיִּים. צַדִּיקִים גְּמוּרִין — נִכְתָּבִין וְנֶחְתָּמִין לְאַלְתַּר לְחַיִּים, רְשָׁעִים גְּמוּרִין — נִכְתָּבִין וְנֶחְתָּמִין לְאַלְתַּר לְמִיתָה, בֵּינוֹנִיִּים — תְּלוּיִין וְעוֹמְדִין מֵרֹאשׁ הַשָּׁנָה וְעַד יוֹם הַכִּפּוּרִים, זָכוּ — נִכְתָּבִין לְחַיִּים, לֹא זָכוּ — נִכְתָּבִין לְמִיתָה. אָמַר רַבִּי אָבִין, מַאי קְרָא: ״יִמָּחוּ מִסֵּפֶר חַיִּים וְעִם צַדִּיקִים אַל יִכָּתֵבוּ״. ״יִמָּחוּ מִסֵּפֶר״ — זֶה סִפְרָן שֶׁל רְשָׁעִים גְּמוּרִין, ״חַיִּים״ — זֶה סִפְרָן שֶׁל צַדִּיקִים, ״וְעִם צַדִּיקִים אַל יִכָּתֵבוּ״ — זֶה סִפְרָן שֶׁל בֵּינוֹנִיִּים.
§ The Gemara goes back to discuss the Day of Judgment. Rabbi Kruspedai said that Rabbi Yoḥanan said: Three books are opened on Rosh HaShana before the Holy One, Blessed be He: One of wholly wicked people, and one of wholly righteous people, and one of middling people whose good and bad deeds are equally balanced. Wholly righteous people are immediately written and sealed for life; wholly wicked people are immediately written and sealed for death; and middling people are left with their judgment suspended from Rosh HaShana until Yom Kippur, their fate remaining undecided. If they merit, through the good deeds and mitzvot that they perform during this period, they are written for life; if they do not so merit, they are written for death. Rabbi Avin said: What is the verse that alludes to this? “Let them be blotted out of the book of the living, but not be written with the righteous” (Psalms 69:29). “Let them be blotted out of the book”; this is the book of wholly wicked people, who are blotted out from the world. “Of the living”; this is the book of wholly righteous people. “But not be written with the righteous”; this is the book of middling people, who are written in a separate book, not with the righteous.