Numbers 10:10-11

10Blow the trumpets in times of gladness, too, sounding them at your annual festivals and at the beginning of each month. And blow the trumpets over your burnt offerings and peace offerings. The trumpets will remind your God of his covenant with you. I am the Lord your God.”

11In the second year after Israel’s departure from Egypt—on the twentieth day of the second month—the cloud lifted from the Tabernacle of the Covenant.