Cross reference
Numbers 10:7
7 But when the congregation is to be gathered together, ye shall blow, but ye shall not sound an alarm.
Joel 2:1
1 Blow ye the trumpet in Zion, and sound an alarm in my holy mountain: let all the inhabitants of the land tremble: for the day of the LORD cometh, for it is nigh at hand;
Numbers 10:3-4
3 And when they shall blow with them, all the assembly shall assemble themselves to thee at the door of the tabernacle of the congregation.
4 And if they blow but with one trumpet, then the princes, which are heads of the thousands of Israel, shall gather themselves unto thee.