LEV187 The fifth way [of repentance] is [as follows]: During the Ten Days of Repentance, one who fears Hashem will be filled with trepidation, knowing that all his deeds are "inscribed in the book" (Avos 2:1), and that at that time He will bring him to judgment for all his actions, for all that is hidden, whether good or bad [Koheles 12:14] This refers to even slight sins (Chagigah 5a) -- for man is judged on Rosh Hashanah and his sentence is sealed on Yom Kippur. When one knows that his judgment will be brought before a king of flesh and blood, he is seized with great trembling, takes counsel with himself, and will assiduously hasten to find a way to save himself [Tehillim 55:9]. It will never enter his mind to turn right or left and be occupied with his other [mundane] concerns. He will disregard [the need] to develop and till his plot of land and to tend to his vineyards [Iyov 24:18]. When troubled times befall him, he will not relax from his readiness to rescue himself, like a deer from the [trapper's] hand (Mishlei 6:5]. As such, how foolish are those who go out to work and to their laborers until evening [Tehillim 104:23] during the Days of Awe [I.e., the Ten Days of Repentance], the days of justice and judgment, not knowing what their judgment will be. Indeed, their hearts should be dwelling on what to answer on the day when their sentence will be rendered, as the pasuk says (Shir haShirim 8:8), "What shall we do for our sister, on the day she is spoken of?" (I.e., a reference to the neshamah, on the Day of Judgment). It is befitting for every God-fearing individual to limit his [mundane] affairs and fill his thoughts with trepidation. He should set aside times, both day and night, to be alone in his chambers, to examine his ways and to analyze them. He should arise during the [latter part of the] night (I.e., the "latter watch of the night (Berachos 3b), when he can more readily find favor in Hashem's eyes (Zeh Hasha'ar), and occupy himself with the pathways of repentance and with improving his deeds. He should pour forth in supplication, offer prayer and psalm, and plead for clemency--for this time is one of finding favor, when prayer is heard, as the pasuk says (Yeshayahu 49:8), "At the time of favor I have answered you, and on a day of salvation I have assisted you." Our Sages, z"l, said (Rosh Hashanah 18a): "'Seek Hashem when he is to be found' (Yeshayahu 55:6)--these are the ten days between Rosh Hashanah and Yom Kippur." It is a positive commandment of the Torah that one arouse his spirit to repentance on Yom Kippur, as the pasuk says: [this verse]. Therefore, the pasuk exhorts us to purify ourselves before Hashem by repenting, that he may grant us atonement on this day, which will lead to our [complete] purification.