With the exception of Purim, postexilic feasts are not presented in the Old Testament. For the most part, they developed in the intertestamental period and are mentioned primarily in the books of the Old Testament Apocrypha.
The Day of Atonement was a time for fasting and cleansing from sin. Traditionally, the high priest made atonement on this day for the sins of the priests, the people, and the sanctuary.
Ro’sh Hashshanah (literally, “head of the year”) the Hebrew new year, ushered in the Feast of Trumpets with the blowing of the ram’s horn. It was the first of the high holy feast days and looked forward to the solemn Day of Atonement which occurred ten days later.
The Feast of Tabernacles came at the end of the harvest and was the outstanding feast of rejoicing in the year. During its seven days the people lived in booths to recall the time Israel spent in the wilderness.
Pentecost, which means “fifty,” is celebrated fifty days after Passover. It is the only one of the three pilgrimage feasts which did not commemorate a specific event in Israel’s history. Eventually it came to be associated with the giving of the Law at Mount Sinai.
The Feast of Passover commemorated the Lord’s deliverance of Israel in Exodus. The Feast of Unleavened Bread, which followed it, kept alive the memory of the affliction of the Israelites and their haste in departing from the land of bondage.
The word sabbath means a time of rest. In Israelite and Jewish religion, times of rest are the weekly Sabbath, the monthly new moon, the sabbatical year, the Year of Jubilee, and special festal Sabbaths. Sabbaths were times of release from the economic bondage of heavy work or constant indebtedness; they were declarations that the needs of the people were supplied not by their labor but by the Lord.