The language of this verse infers that the people had scouts or connections which tipped them off about the activities of the king's army. Later on, we learn that the Lord was their informant. The account of Alma reads, Now Alma, having been warned of the Lord that the armies of king Noah would come upon them, and having made it known to his people, therefore they gathered together their flocks, and took of their grain, and departed into the wilderness (Mosiah 23:1, italics added).