Mosiah 23:21 - 23:25

Mosiah 23:21 Nevertheless the Lord seeth fit to chasten his people; yea, he trieth their patience and their faith.

Even thought everything seemed to be going Alma’s way, the Lord was going to try them some more.
[Their trials were not quite over yet. He wanted them to know that the Lord was the one who delivered them, not their own cleverness. The coming episode address the issue why bad things happen to good people. It just maybe that they are not as good as they might think. They maybe going through the motions, but deep in their souls they may not be as committed as they might think. Convictions come often times by pushing folks to the brink of failure then pulling them back. Trials allow people to see they are better than they thought they were. This confidence or success often times gives people even more desire to do go to keep up the feelings of knowing you can handle it which is inspiring in and of itself.]

Mosiah 23:22 Nevertheless—whosoever putteth his trust in him the same shall be lifted up at the last day. Yea, and thus it was with this people.

(Here is an assessment by Mormon.) They who put their lives into the hands of the Lord will be guided in the right paths. Here in the next few verses will be an example of that principle.

Mosiah 23:23 For behold, I will show unto you that they were brought into bondage, and none could deliver them but the Lord their God, yea, even the God of Abraham and Isaac and of Jacob.

Mormon will show us in this account how the Lord can deliver people. For these people of Alma will find themselves in the hands of the Lamanites once again and their delivery will only come from the direct intervention of the Lord. They will not be able to free themselves on their own.

Mosiah 23:24 And it came to pass that he did deliver them, and he did show forth his mighty power unto them, and great were their rejoicings.

The Lord did, indeed, deliver them and did show just how much control He had over situations that seem to be hopeless. This was a confidence builder to all who put their trust in the Lord.

Mosiah 23:25 For behold, it came to pass that while they were in the land of Helam, yea, in the city of Helam, while tilling the land round about, behold an army of the Lamanites was in the borders of the land.

Because all of a sudden, the Lamanites were upon them while they were working in the fields.