3 Nephi 4:16

and in the twenty and first year they did not come up to battle, but they came up on all sides to lay siege round about the people of Nephi; for they did suppose that if they should cut off the people of Nephi from their lands, and should hem them in on every side, and if they should cut them off from all their outward privileges, that they could cause them to yield themselves up according to their wishes.

In the twenty-first year, they didn’t come to battle. Instead, they came from all sides to surround the Nephites. They thought if they cut the Nephites off from their lands and trapped them on every side, and stopped them from getting anything from outside, they could make them give up.

In the twenty-first year, instead of attacking, they surrounded the Nephites on all sides—laying siege. They thought that if they could cut the Nephites off from their lands and trap them, blocking all their outside access, they could force them to surrender.