Numbers 10:10-11

10On the day of your gladness also, and at your appointed feasts and at the beginnings of your months, you shall blow the trumpets over your burnt offerings and over the sacrifices of your peace offerings. They shall be a reminder of you before your God: I am the Lord your God."

11In the second year, in the second month, on the twentieth day of the month, the cloud lifted from over the tabernacle of the testimony,