Leviticus 23:25
Do no regular work, but present a food offering to the Lord. The concise regulation for the Festival of Trumpets: no regular work, food offering. The brevity of the Trumpets regulation compared to the extended regulations for the other festivals communicates that the Festival of Trumpets is primarily a preparatory day — the announcement of the sacred month whose significance lies in the Day of Atonement (day 10) and the Festival of Tabernacles (day 15) that follow.