Alma 43:53

therefore when Zerahemnah saw the men of Lehi on the east of the river Sidon, and the armies of Moroni on the west of the river Sidon, that they were encircled about by the Nephites, they were struck with terror.

When Zerahemnah saw Lehi’s men on the east side of the river Sidon and Moroni’s armies on the west side of the river, he saw that the Nephites surrounded them. They were filled with fear.

When Zerahemnah saw Lehi’s men on the east side of the Sidon and Moroni’s armies on the west, and realized they were completely surrounded by Nephites, terror struck them.