Kitto's Popular Cyclopedia of Biblial Literature
Atonement Day of
Atonement, Day of (day of pardon, Leviticus 23:27; Leviticus 25:9). Though perhaps originally meant as a temporary day of expiation for the sin of the golden calf (as some would infer from Exodus 33), yet it was permanently instituted by Moses as a day of atonement for sins in general; and this day—the 10th of Tishri (our September)—is indeed the only fast ordained by Moses. This great fast commenced at sunset of the previous day, and lasted twenty-four hours, that is, from sunset to sunset. The ceremonies observed on this occasion are minutely described in Leviticus 16, and were of a very laborious character, especially for the high-priest, who had to prepare himself during the previous seven days in nearly solitary confinement for the peculiar services that awaited him, and abstain during that period from all that could render him unclean, or disturb his devotions. The most remarkable ceremony of the day was the entrance of the high-priest into the Sanctuary, a thing not allowed on any other day, and to which Paul alludes, Hebrews 9:7.
The other duties of the high-priest on that day consisted in frequent washings, changing his clothes, lighting the lamps, burning incense, etc.; which operations commenced soon after midnight of the 10th of the seventh month (Tishri). The ceremonies of worship peculiar to this day alone (besides those which were common to it with all other days) were: 1. That the high-priest, in his pontifical dress, confessed his own sins and those of his family, for the expiation of which he offered a bullock, on which he laid them; 2. That two goats were set aside, one of which was by lot sacrificed to Jehovah, while the other (Azazel), which was determined by lot to be set at liberty, was sent to the desert burdened with the sins of the people (Leviticus 16).
On this day also the high-priest gave his blessing to the whole nation; and the remainder of the day was spent in prayers and other works of penance.
Among the present orthodox Jews, for the scape-goat of old, a cock seems to have been substituted, which they call pardon, atonement, and which, on the eve of the day of Atonement, they turn three times round their head, each time saying (in Hebrew) that the cock is to be sacrificed instead of them, after which it is slaughtered and eaten. Towards evening of the 9th of Tishri, and before they take the last meal for the next twenty-four hours, they repair to the synagogue, and each inflicts upon his neighbor thirty-nine blows with a piece of leather. Most of the Jews on that day (of atonement) wear a white gown—the same shrouds in which they are buried; while all of them are obliged to stand the whole day without shoes, or even slippers.
Kitto, John, ed. Entry for 'Atonement Day of'. "Kitto's Popular Cyclopedia of Biblial Literature". https://www.studylight.org/encyclopedias/eng/kbe/a/atonement-day-of.html.