3 Nephi 4:6

And they durst not spread themselves upon the face of the land, insomuch that they could raise grain, lest the Nephites should come upon them and slay them; therefore Giddianhi gave commandment unto his armies, that in this year they should go up to battle against the Nephites.

They didn’t dare spread out across the land to grow grain. The Nephites would come and kill them. So Giddianhi told his armies to go fight the Nephites that year.

They didn’t dare spread out across the land to grow crops, because the Nephites would hunt them down and slaughter them. So Giddianhi commanded his armies to march against the Nephites that year.