3 Nephi 4:9

And it came to pass that when the armies of Gaddianhi saw this, they began to shout with a loud voice, because of their joy; for they had supposed that the Nephites had fallen with fear, because of the terror of their armies;

When Giddianhi’s armies saw this, they began to shout loudly with joy. They thought the Nephites had fallen down because they were scared of their armies.

When Giddianhi’s armies saw this, they started shouting for joy. They thought the Nephites had collapsed in terror at the sight of them.