During the period of Aseret Yemei Teshuva (the "Ten Days of Repentance" from Rosh Hashana through Yom Kippur) we recite the "Avinu Malkenu" prayer after the Amida during both Shacharit and Mincha. Our practice is to recite this prayer even on Shabbat.
Included in this prayer is the seemingly peculiar request, "Avinu Malkenu Kotvenu Be'sefer Zachuyot" – "Our Father, our King, inscribe us in the book of merits." The Chafetz Chayim (Rabbi Yisrael Kagan, Lithuania, 1835-1933) asked, how can we ask God to inscribe us in the book of merits? A person's inclusion in this book depends solely on his conduct: if he has ample merit, then God will assuredly inscribe him in the book of merit; if he has not accrued sufficient merit, then he has no right to ask to be inscribed in this book. What, then, do we mean when we ask, "Inscribe us in the book of merits"?
The Chafetz Chayim suggested that in this prayer we refer to the many Mitzvot we performed with incomplete sincerity. Very often we perform Mitzvot for the purpose of honor, for our fame and reputation, or for some other ulterior motive. According to the principles of strict justice, these Mitzvot are not worthy of inclusion in the book of merits. We therefore beseech God that He look upon us compassionately and afford us the benefit of the doubt that we truly desire to fulfill His will but are affected by all types of distractions and pressures that divert our attention away from the pure, sincere service of God. If He assesses our Mitzvot with compassion and understanding, then they are indeed inscribed in the book of merits, and this is our request in "Avinu Malkenu."
Rabbi Efrayim Zalman Margaluyot (Russia, 1760-1828) suggested a different interpretation, that in this prayer we ask God to inscribe our sins in the "book of merits." The Gemara comments in Masechet Yoma that Teshuva (repentance) has the capacity to transform our sins into merits. We thus beseech God to grant us the ability to properly repent so that our sins will be transformed into merits, such that even they can be included in our "Sefer Zachuyot" – our "book of merits."
