First, Israel's guidance was God Himself in the form of a cloud. Second, the children of Israel were guided by the two trumpets (10:1-10). Because the trumpets made a loud sound, they could become a means of guidance.
"Jehovah spoke to Moses, saying, Make for yourself two silver trumpets; of hammered work you shall make them" (vv. 1-2a). In typology, silver signifies Christ's redemption. The fact that the trumpets were made of hammered work indicates that they were made through beating.
The two silver trumpets were to be used for summoning the assembly and for having the camp set out (v. 2b).
The blowing of both trumpets was for assembling. "When both are blown, all the assembly shall assemble themselves to you at the entrance of the tent of meeting" (v. 3).
The blowing of just one trumpet was for the assembling of the leaders. "But if they blow only one, then the leaders, the heads of the thousands of Israel, shall assemble themselves to you" (v. 4).
The blowing of an alarm was for the camps on the east side to set out. "When you blow an alarm, the camps that are encamped on the east side shall set out" (v. 5).
The blowing of the second alarm was for the camps on the south side to set out. "When you blow an alarm the second time, the camps that are encamped on the south side shall set out. An alarm is to be blown whenever they are to set out" (v. 6).
Here in Numbers the sound of the trumpet was called an alarm because, in God's thought, the children of Israel were continually at war. At any time they could hear the alarm for fighting. When they moved, they moved in a fighting way. This signifies that our Christian walk, our Christian move, is a fighting move. However, quite often we have been negligent in this matter and have suffered as a result. Concerning certain moves, we suffered a great deal because we did not have the consciousness that we were in a battle. We are always at war, and therefore we should constantly be under the sounding of the alarm.