Yom Kippur, the Sabbath of Sabbaths, is observed the tenth day of the Hebrew month of Tishri, which falls in September or early October in the secular calendar. Yom Kippur is reckoned to be the most important holiday of the Jewish year. Many Jews, who do not observe any other Jewish custom will refrain from work, fast and/or attend synagogue services on this day. The holiday is instituted in Leviticus 16. The first Yom Kippur took place after Moses returned from his second trip to Mt. Sinai with the replacement set of tablets containing the Ten Commandments. Moses descended the mountain on the tenth of Tishri. Upon returning, Moses found the nation truly repentant and announced that G-d had forgiven them. He decreed that the tenth of Tishri would remain a day of atonement for all generations.
And this shall be an eternal law for you. Each year on the tenth day of the seventh month you must fast and do no work. This is true of the native born and of the proselyte who comes to join you. This is because on this day you shall have all your sins atoned, so that you will be cleansed. Before G-d you will be cleansed of your sins. It is a Sabbath of Sabbaths to you, and a day upon which you must fast. This is a law for all time. (Leviticus 16:29-31)
The name "Yom Kippur" means "Day of Atonement”. It is a day set aside to "afflict the soul," to atone for the sins of the past year. Divine forgiveness was only possible after the entire congregation acknowledged and sought forgiveness for their behaviour. It was also a symbolic reminder of what G-d could do to them if they did not repent. During the time of the temple service there was a very specific way in which Yom Kippur was celebrated. A week before the holiday, the High Priest would leave his home to live inside the temple. That week, he would perform all the temple duties himself. In addition, he would study two Torah portions and learn one by heart to make sure he didn't make any mistakes. The night before, the High Priest would stay up all night learning Torah and preparing himself spiritually. If he fell asleep, young priests woke him up by reciting psalms. Sometimes they In the morning, he would put on his priestly clothes and go about the daily morning service, including the morning's sacrifice, the lighting of the menorah and the burning of incense. Then he would wash his hands and feet in a golden basin. Afterwards, he took a bath, a ritual he repeated throughout the day. Then, the High Priest would change into a simple robe made of white linen and walk over to a young bull and recite for himself and for his family the first of three confessional prayers. Three times during the prayer he pronounced the “Shem Hameforash”, (the name by which G-d identified himself to Moses at the burning bush, and to this day, remains unpronounceable), instead of the usual "Adonai," meaning L-rd.
The crowd of worshippers, in awe of the moment, fell on the floor, and cried out in loud voices, "Baruch Shem Kevod Malchuto Le'olam Va'ed," (Blessed be the Name, the glory of His kingdom forever and ever) a phrase, that even today, is only said out loud on Yom Kippur. The High Priest then walked over to two identical goats. Through a lottery, one goat was chosen as a sacrifice to G-d, and the other, a scapegoat, with red wool tied around its horns, would later be sent out into the wilderness, a symbol of the collective sins of the people. The young bullock was then slaughtered and its blood collected in a basin for later use, would make the High Priest stand all night on the cold, stone floor.
Then the most important part of the ceremony takes place. The High Priest walked up a special ramp (so temple priests could ascend with modesty in tact) to the altar, filled a gold pan with coals and a golden ladle with incense. Then, with everyone watching, he walked into the “Kodesh K’dashim”. This is the Holy of Holies, the inner sanctuary where G-d's spirit dwelled and where no one but the High Priest entered except on Yom Kippur. Once inside, he lit the incense, and if all went well, emerged unscathed from the inner chamber. The ritual continued with the High Priest sprinkling blood on the curtain of the Holy of Holies as an act of purification. Next, the remaining goat was slaughtered and additional blood sprinkled on the curtain and around the base of the altar.
The scapegoat was then led through the temple's gate to a waiting priest whose job it was to take it to predetermined spot about ten to twelve miles away. Along the way, there were ten stations with food or drink in case the tired priest needed to break his fast. When the priest came to the final station, he pushed the goat off a cliff. Using a system of signal flags, the priest leading the animal would message back to the temple that the sins of the people were forgiven as the red wool around the goat's horns turned miraculously white.
Although the special Yom Kippur service was concluded, the regular afternoon temple service still had to be completed. The High Priest again washed and changed his clothes, lit the menorah and burned the incense. When he finally went home, he was accompanied by well wishers, who after praying and fasting all day, wanted to thank the High Priest for a successful Yom Kippur. At home, however, he could still not relax. As High Priest, it was his duty to invite fellow priests and dignitaries to a feast. Today, when families return home from the long day of fasting and praying, they also come home to break-the-fast meal, usually dairy, joined by family and friends.