Mosiah 24:6 - 24:10

Mosiah 24:6 But they taught them that they should keep their record, and that they might write one to another.

But Amulon did teach them to read and write so they could keep records and correspond with each other.

Mosiah 24:7 And thus the Lamanites began to increase in riches, and began to trade one with another and wax great, and began to be a cunning and a wise people, as to the wisdom of the world, yea, a very cunning people, delighting in all manner of wickedness and plunder, except it were among their own brethren.

With this ability to communicate with each other, through the written word, they began to do business with one another. They increased in worldly wisdom especially on how to increase their material possessions. They were also good at cheating other groups they had relations with, but were ethical with each other.
[Fairly typical of people of business. They are fair with close associates, but didn"t mind getting all they can from others not of their immediate circle of friends or business associates.]

Mosiah 24:8 And now it came to pass that Amulon began to exercise authority over Alma and his brethren, and began to persecute him, and cause that his children should persecute their children.

As Amulon took over as governor of Alma’s people under the authority of king Laman, they began to persecute them. Even the children of Amulon made life miserable for Alma’s children.

Mosiah 24:9 For Amulon knew Alma, that he had been one of the king’s priests, and that it was he that believed the words of Abinadi and was driven out before the king, and therefore he was wroth with him; for he was subject to king Laman, yet he exercised authority over them, and put tasks upon them, and put task-masters over them.

Amulon knew who Alma was and that he was one of king Noah’s priests and that he had believed in the words of Abinadi. Amulon being angry at the lost of his position in king Noah’s court and the easy life he had there, now could take out his frustration on Alma and his people. Amulon increased their work load of public works and made sure they did their work with overseers. This Amulon did without the consent of king Laman.

Mosiah 24:10 And it came to pass that so great were their afflictions that they began to cry mightily to God.

The increased work load cause the people of Alma to pray for relief.