The Talmud says that Yom Kippur is one of the two best days in the Jewish calendar, the other respectively being Tu B’AV (Taanit 26b). The main reason why this may be, is that one has the opportunity to atone for past transgressions, especially between man to G-d desecrations. In fact Yom Kippur atones for many transgressions (Keritot 7).
However if one wants to atone for transgressions done against a fellow man, they need to go as far as begging with an apology and may even have to correct the transgression that may have taken place against his fellow through financial means. The Talmud teaches us that if one damaged his friend’s property, although one compensates him for the damage he has caused him, the one who caused the damage is not forgiven until he asks forgiveness from the damaged party (Bava Kama 92a).
Yom Kippur is a day in which one does not perform any of the labor one is also not allowed to perform on Shabbat. Additionally one is not allowed to eat or drink on this day. One is not allowed to wear leather shoes on this day as well as not being allowed to wash many parts of the body and to anoint themselves with oil (Yoma 8:1 Mishna (Yoma 73b)). It is a day that married couples should refrain from having relations.
One spends the majority of the day in the Synagogue, the ‘Kol Nidrei’ evening prayer for Yom Kippur comprises also of Selichot, as well as Vidduy (confessions). It is customary after the service to learn the Mishna section of ‘Yoma,’ as this very much details the procedure of the Yom Kippur service in the days of the Temple.
The next day, also comprises of Selichot, as well as Morning, Mussaf and Mincha services.
During the morning service of Yom Kippur we recite sections of Parshat Acharei Mot (Vayikra 16:1-34). This parshah discusses the service done by the Kohen Gadol on the holiest day of the year, Yom Kippur, also known as the Day of Atonement.
This reading relates how a Kohan may not enter the Mikdash unnecessarily, after mentioning what happened to Nadav and Avihu.
Much preparation was made before the Yom Kippur service in the days of the Temple; the most important service would be of the Kohen Gadol, going into the Holy of Holies. On Erev Yom Kippur the sages would instruct and teach the Kohen Gadol what he would be doing the following day in the most precise manner. On the night of Yom Kippur itself, the Kohen Gadol was to stay up the whole night, reading various chapters from the Tanach (including the books of Daniel, Chronicles and Ezra), as this was a time for atonement, the Kohen Gadol was utilizing his time absorbing in Torah.
The Yom Kippur service was huge, starting off with the daily morning service, then the high priests Mincha offering, then the Mussaf of Yom Kippur, then the first confession. The Yom Kippur service progressed with a service featuring a lottery; two identical goats were brought and two lots were drawn, one of Azazel and the other to Hashem (Vayikra 16:8). The goat that was selected to Hashem was to be a sacrifice to Hashem, and the goat selected for ‘Azazel,’ would be thrown off a cliff in the wilderness.
The Yom Kippur Service progressed with the slaughtering of the Kohen Gadol's bullock and then the main part of Yom Kippur, the service in the Holy of Holies, where the Kohen Gadol would go in and then after carrying out a ketoret service, he would go into the Kodesh section and beseech Hashem for forgiveness in behalf of the Jewish nation. If the Kohen Gadol and the people were not worthy it could mean the death of the Kohen Gadol.
During the 410 year era of the First Temple there were 18 Kohen Gadolim and in the 420 year era of the second Temple, there was a whopping 300 Kohen Gadolim (Yoma 9a)! The position of High priest became some what corrupt during the Second Temple era, very much reflected by the fact so many of them died in the Yom Kippur service as they were not worthy of the position.
Next up, the Kohen Gadol would sprinkle the blood of his Bullock, then he would slaughter the goat to Hashem, sprinkle the goats blood and then sprinkle the blood of the sacrifices onto the dividing curtain and the Golden Alter (Shemot 30:1/10), after pushing the goat off cliff in the woldreness, the rest of the Mussaf service was carried out, the Kohen Gadol read from the Torah, there was the offering of the Rams, burning of the inner organs, the daily incense (Vayikra 16:12) and concluded by the Kohen Gadol's daily Mincha offering.
Yom Kippur is a day of fasting and abstention of work. It was on the day of Yom Kippur that Moshe came down from heaven after his third stay there with the second set of tablets and G-d forgave the Jewish people from the sin of the Golden Calf (Shabbat 88b).
Also we will be reading the book of Jonah as the Haftorah, featuring the famous story of Jonah and the Whale (Jonah 1:1- 4:11). Jonah was given a command by Hashem to persuade the community of Ninveh to repent from their huge transgression they were committing (Sanhedrin 61), however as many were gentiles, he was worried that if they would repent, it would bring a prosecution against the Jewish people if they would successfully repent.
Jonah initially refused, in retribution, a whale swallowed up Jonah for three days, while inside the belly of the whale Jonah repented and ultimately came out alive from the whale and brought the whole city to repent. From this story we learn how important it is for one to repent at the first possible opportunity to do so.
Hope you all have a meaningful fast, this Dvar Torah is dedicated for a Bracha (Blessing) for Moshe Ben Yael Leah, so that he will grow up to become very great in Torah and a very good person, with countless of righteous descendants and descendants of descendants, please everyone pray that this will happen!