Occasions of commemoration and religious thanksgiving. Regular days were set aside for Hebrews when they could relax and enjoy themselves with music and dancing. There were thanksgivings to God for blessings and for material relief for the poor and oppressed. Apart from the weekly Sabbath, the release of slaves was prescribed for every seventh year (Exod. 21: 2–6) and debts were to be remitted (Deut. 15: 1–6), while in the year of jubilee property was to return to the original owner. There were also new moon festivals (Lev. 23: 23–5).
But the three greatest festivals were first, the Passover and Unleavened Bread, kept for a whole week in the first month (Exod. 12) in commemoration of the Exodus from Egypt which has always given hope and self‐esteem to the Jewish people through all the vagaries of their history; this festival was established in the Temple under Josiah's reforms (622 BCE) and further changes were made by the priestly laws after the Exile (Num. 28: 19–24). Secondly, the feast of Weeks took place at the beginning of wheat harvest (Deut. 16: 9–12) seven weeks after Passover, at the end of a busy agricultural season; and thirdly, the feast of Booths, or Tabernacles, was celebrated from the 15th to the 22nd of the seventh month (late September), and was the Israelite Harvest Thanksgiving: the ritual requirement to dwell in booths reflected God's protection of the people during their wanderings in the wilderness (Lev. 23: 39–43). At this feast Solomon's Temple was dedicated (1 Kgs. 8: 2). After Josiah's reforms crowds of pilgrims visited the Temple. Such were the numbers that it was probably essential for many to erect temporary booths while waiting their turn. After the Exile this practical necessity was given its theological justification (Neh. 8: 14).
Later feasts were ordered: the feast of Dedication was in thanksgiving for the rededication of the Temple by Judas Maccabaeus on the 25th of Chislev (December) in 164 BCE, and called Hanukkah (1 Macc. 4: 59; John 10: 22, but this was not mentioned in the Hebrew OT). The feast of Purim in Adar (late February), connected with the book of Esther, was perhaps borrowed from the celebrations of New Year by the Persians. It became a minor holiday for Jews.
The gospel of John seems to be written round Jesus' visits to Jerusalem for the feasts, and Paul reports that the weekly celebration of the Lord's death was initiated as a commemoration of the Last Supper at Passover (1 Cor. 11: 24). Christians in the early Church soon began to hold their regular worship on Sunday as a weekly feast in honour of the Resurrection, instead of meeting on the Sabbath.