Alma 62:12

And it came to pass in the commencement of the thirty and first year of the reign of the Judges over the people of Nephi, Moroni immediately caused that provisions should be sent, and also an army of six thousand men, should be sent unto Helaman, to assist him in preserving that part of the land;

At the start of the thirty-first year of the judges over the people of Nephi, Moroni right away sent food and an army of six thousand men to Helaman. This was to help him keep that part of the land safe.

Early in the thirty-first year, Moroni immediately sent provisions and six thousand men to Helaman to help him hold that part of the land.