Alma 43:1 - 43:5
Alma 43: 1 And now it came to pass that the sons of Alma did go forth among the people, to declare the word unto them. And Alma, also, himself, could not rest, and he also went forth.
After some rest, the sons of Alma continued in their ministries. Alma as well went forth among the people as he could not just sit around letting others doing what he could do as well.
Alma 43: 2 Now we shall say no more concerning their preaching, except that they preached the word, and the truth, according to the spirit of prophecy and revelation; and they preached after the holy order of God by which they were called.
Mormon will not comment anymore on the efforts of Alma and those who were called to preach the gospel of repentance to the people. They did so with the authority that had been given them along with the spirit of prophecy and revelation.
Alma 43: 3 And now I return to an account of the wars between the Nephites and the Lamanites, in the eighteenth year of the reign of the judges.
Mormon will now continue the narative of the wars between the Nephites and the Lamanites in the 18th year of the reign of the judges.
Alma 43: 4 For behold, it came to pass that the Zoramites became Lamanites; therefore, in the commencement of the eighteenth year the people of the Nephites saw that the Lamanites were coming upon them; therefore they made preparations for war; yea, they gathered together their armies in the land of Jershon.
The Zoramites had aligned with the Lamanites and were making preparations to attached the Nephites. The Nephites were getting prepared themselves as they had knowledge of what the Lamanites were doing. The Nephites concentrated their armies in the land of Jerson as they knew that is where the Lamanties would attach first.
Alma 43: 5 And it came to pass that the Lamanites came with their thousands; and they came into the land of Antionum, which is the land of the Zoramites; and a man by the name of Zerahemnah was their leader.
The Lamanite armies, under the command of a man named Zerahemnah, gathered in the land of Antionum. From there they would attach the Nephites in the adjoining land of Jershon.