Repetitive resumption is one way for an ancient scribe to bracket a narrative aside. Here is a description from the article linked in the previous sentence:
How is the reader going to be able to jump back into the main story line once this is done? How does the scribe keep the reader from getting lost? Enter the ancient scribal technique of Weideraufnahme, also called a resumptive repetition or epanalepsis.An example of this technique from the Old Testament can be found in Genesis 37:28, 36 and Genesis 39:1. These verses contain the same information about Joseph being sold to Potiphar. The verses bracket chapter 38, which tells a different story related to Judah.
Simply put, after including the note, parenthetical remark or supplementary source, the ancient scribe would restate or paraphrase the last point in the narrative before the extra piece was added.
The author of this article points out that this technique, which was probably very useful to an ancient reader, can be quite confusing to a modern reader.
Mormon uses this technique as well. Here is an example, with the repeated information in yellow and the side comment in red:
6 So that when he had finished his work at Melek he departed thence, and traveled three days’ journey on the north of the land of Melek; and he came to a city which was called Ammonihah.
7 Now it was the custom of the people of Nephi to call their lands, and their cities, and their villages, yea, even all their small villages, after the name of him who first possessed them; and thus it was with the land of Ammonihah.
8 And it came to pass that when Alma had come to the city of Ammonihah he began to preach the word of God unto them. (Alma 8)
Here are two additional examples from the story of Korihor:
6 But it came to pass in the latter end of the seventeenth year, there came a man into the land of Zarahemla, and he was Anti-Christ, for he began to preach unto the people against the prophecies which had been spoken by the prophets, concerning the coming of Christ.
7 Now there was no law against a man’s belief; for it was strictly contrary to the commands of God that there should be a law which should bring men on to unequal grounds.
8 For thus saith the scripture: Choose ye this day, whom ye will serve.
9 Now if a man desired to serve God, it was his privilege; or rather, if he believed in God it was his privilege to serve him; but if he did not believe in him there was no law to punish him.
10 But if he murdered he was punished unto death; and if he robbed he was also punished; and if he stole he was also punished; and if he committed adultery he was also punished; yea, for all this wickedness they were punished.
11 For there was a law that men should be judged according to their crimes. Nevertheless, there was no law against a man’s belief; therefore, a man was punished only for the crimes which he had done; therefore all men were on equal grounds.
12 And this Anti-Christ, whose name was Korihor, (and the law could have no hold upon him) began to preach unto the people that there should be no Christ. (Alma 30)
And another at the end of the story:
56 And it came to pass that the curse was not taken off of Korihor; but he was cast out, and went about from house to house begging for his food.For more examples and additional information, this link is useful.
57 Now the knowledge of what had happened unto Korihor was immediately published throughout all the land; yea, the proclamation was sent forth by the chief judge to all the people in the land, declaring unto those who had believed in the words of Korihor that they must speedily repent, lest the same judgments would come unto them.
58 And it came to pass that they were all convinced of the wickedness of Korihor; therefore they were all converted again unto the Lord; and this put an end to the iniquity after the manner of Korihor. And Korihor did go about from house to house, begging food for his support. (Alma 30)
Hat Tip: Brant Gardner