"Make two silver trumpets for yourself; you shall make them of hammered work; you shall use them for calling the congregation and for directing the movement of the camps.
Numbers 10:2
Surrounding context
10:1 And the LORD spoke to Moses, saying:
10:2 "Make two silver trumpets for yourself; you shall make them of hammered work; you shall use them for calling the congregation and for directing the movement of the camps.
10:3 When they blow both of them, all the congregation shall gather before you at the door of the tabernacle of meeting.