The Sharia of Moses in the TORA
Part 1 - The 248 Positive Commandments of the Tora
59 - BLOWING THE TRUMPETS IN THE SANCTUARY
Numbers 10:10 -- “Also in the day of your gladness, in your appointed feasts, and at the beginning of your months, you shall blow the trumpets over your burnt offerings and over the sacrifices of your peace offerings; and they shall be a memorial for you before your God: I am the LORD your God.”
The provisions of this commandment are explained in the Sifre, in Rosh Hashanah and Taanioth.