Numbers 10:9
And if you go to war in your land against the enemy that oppresses you, then you shall blow an alarm with the trumpets; and you shall be remembered before the LORD your God, and you shall be saved from your enemies.
Torrey's Topical Textbook—AKJV

Numbers 31:6
And Moses sent them to the war, a thousand of every tribe, them and Phinehas the son of Eleazar the priest, to the war, with the holy instruments, and the trumpets to blow in his hand.
Torrey's Topical Textbook—AKJV

2 Chronicles 13:13,14
But Jeroboam caused an ambush to come about behind them: so they were before Judah, and the ambush was behind them.
Torrey's Topical Textbook—AKJV