2. The very names of these days show that they are special for repenting. While there are no limits on repenting and any time is good, these days are especially good for repenting. As our sages say on the verse in Isaiah: “Seek G-d when He is around, call Him when He is close”— this refers to the ten days between Rosh Hashanah and Yom Kippur. The Rambam writes about the Ten Days of Repentance: “Although repenting and calling out to G-d is always timely, it is especially auspicious during the ten days from Rosh Hashanah until Yom Kippur, and is immediately accepted.”
3. It is a positive Torah commandment to repent before Yom Kippur, as the verse states: “Purify yourself before G-d.” The Code of Jewish Law (Shulchan Aruch) states: “A man should scrutinize his deeds and repent of his misdeeds, increase his Torah study, fulfill commandments, give charity and reduce his business affairs.”
4. The Gates of Repentance are never locked since the Jewish approach is that sins should be eradicated instead of those who commit the sins. This view is expressed in the Jerusalem Talmud as follows:
“They asked Wisdom, ‘What is the punishment of a sinner?’ It said: 'Evil will pursue the sinners.” (Proverbs 13:21) They asked Prophecy, ‘What is the punishment of a sinner?’ It said, 'The soul that sins shall die.” (Ezekiel 18:4) They asked the Torah, ‘What is the punishment of a sinner?’ It said, ‘Let him bring a sacrifice and gain atonement.’ They asked the Almighty: ‘What is the punishment of a sinner?’ He said, ‘Let him repent and gain atonement, as it is written (Psalms 25:8): 'G-d is good and straight, therefore He shows sinners the way’ – He shows sinners how to repent.”
5. During the Ten Days of Repentance, the conclusion of several blessings change and special supplications are inserted.
The 4 insertions in the Shemoneh Esreh prayer include:
“Remember us for life, King Who desires life, and inscribe us in the Book of Life, for Your sake, living God” – before concluding the first blessing.
“Who is like you, merciful Father, Who remembers His creatures for life, in His mercy.” – before concluding the second blessing.
“Inscribe all the children of Your covenant for a good life.” – before concluding the blessing of Modim.
“In the book of life, blessing, peace, and abundant sustenance, may we be recalled and inscribed before you, we and all Your people, the house of Israel, for a good life and peace!” – before concluding the blessing of Sim Shalom.
The 2 changes at the end of blessings are:
in the third blessing: “Holy King” instead of “Holy G-d”.
and in the 11th blessing: “the King of Justice” instead of “King Who loves righteousness and justice.”
In addition, the custom is to say at the end of the Shemoneh Esreh, “Who makes the peace” instead of “Who makes peace” as is said throughout the year. This change is implemented in Kaddish too.
Another change in Kaddish is that we say “L’aila u’l’aila” (G-d is “far above”), instead of “l’aila” (is “above”) , as is said throughout the year.
The custom to recite Selichot (penitential prayers) is intended especially for these days when we increase our pleadings. Many communities spend more time reciting Selichoton these days than during the Selichot recited before Rosh Hashanah.
6. After the morning and afternoon prayers, we add the prayer Avinu Malkeinu (“Our Father, our King”) which is also supplications and requests.
7. These days should primarily be devoted to repenting for sins that one person did to another. The Shulchan Aruch states that “one especially has to fix things between him and his fellow man, for which there is no forgiveness until he returns what he stole, reconciles with the person and forgives him.”
8. “It is also proper that a person keep stringencies during these days that he doesn’t keep all year round, because we are also asking G-d to treat us mercifully, beyond the measure of the law.”
9. Some have the custom to say in Grace After Meals, “May the Merciful One make this year one of good and blessing for us.”
10. Some have the custom to build their sukkah and buy the four species for Sukkot during the Ten Days of Repentance, so that this commandment will add to their merits.