“ And it shall be that when they make a long blast with the ram's horn, and when you hear the sound of the trumpet, all the people shall shout with a great shout, and the wall of the city will fall down flat, and the people shall go up, every man straight before him.”
On the seventh day, once the city had been surrounded seven times, a long distinguishing blast was to be made on the trumpet of ram's horn. Then all the people (probably indicating all the men of war) were to shout with a great shout and the walls would collapse so that all the armed men could go straight before them into the city. Horns always symbolise power (they are the effective armament of both domestic and wild beasts) so that here there may be in the ‘seven rams' horns' the idea of expressing the divine perfection of the power of YHWH.
The long blast on the ram's horn was possibly to symbolise the trumpet sound of YHWH as in Exodus 19:16; Exodus 19:19; Exodus 20:18, introducing His power revealed in what was about to happen. In Psalms 47 the sound of the ram's horn indicates the going forth of YHWH as King (Psalms 47:5-7), a psalm which also links it with the people's shout of triumph (Joshua 6:1; Joshua 6:5), when He goes forth to subdue the nations and to grant an inheritance to His people (Joshua 6:3-4), resulting in His reign over all things. Jericho was but the beginning of the revelation of His power.