Once they had learned how to deal with property and deal with neighborly relations, the next thing they had to do was to look after the family. Benjamin taught his people, and consequently us, that they were to teach their children the laws of God. They could not be worthy to enter into this covenant if they would not agree to teach the children the laws of the covenant. Building righteous homes is a crucial part of entering into that covenant.
This requirement—that parents who enter into the covenant have to be willing to agree to teach their children these principles—is also found in Deuteronomy 4:9, where Moses is promulgating the covenant with all of Israel. He said, "Only take heed to thyself, and keep thy soul diligently, lest thou forget the things which thine eyes have seen, and lest they depart from thy heart all the days of thy life: but teach them thy sons, and thy sons’ sons," and at the end of Deuteronomy 4:10, he said, "That they may learn to fear me all the days that they shall live upon the earth, and that they may teach their children."
Also, two chapters later, in Deuteronomy 6:6–7, it says, "And these words, which I command thee this day, shall be in thine heart: And thou shalt teach them diligently unto thy children, and shalt talk of them when thou sittest in thine house, and when thou walkest by the way, and when thou liest down, and when thou risest up." Alma used the same phraseology. He knew this because it was in the Law of Moses which they were living strictly. Deuteronomy 6:8–9 continues, "And thou shalt bind them for a sign upon thine hand, and they shall be as frontlets between thine eyes. And thou shalt write them upon the posts of thy house, and on thy gates," so that as people came in and out of the house, they would remember those "words".
Do you think that Benjamin knew Deuteronomy? I think so. It was a covenantal restatement of the law of Moses. Benjamin was clearly aware of Deuteronomy 17 and the paragraph of the king, which he paraphrased in Mosiah 2. Now he turns to family duties as an integral part of his royal covenant.
Did Benjamin recognize that parents teaching their children is an implicit part of the covenant? We could think that this statement was just a random moralizing comment by Benjamin. But here Benjamin is doing more than giving nice advice. He has already mentioned that Christ’s Atonement embraces the eternal welfare of little children (Mosiah 3:16–17, and now he adds: "Not only shall we all be happy at home," but children need to be raised in righteousness. They are part of the covenant too. Much depends on their condition and future faithfulness, and so there is a lot going on here.
Book of Mormon Central, "Did Alma Counsel His Sons During the Passover? (Alma 38:5)," KnoWhy 146 (July 19, 2016).
Book of Mormon Central, "What Does the Book of Mormon Teach about Families? (Mosiah 25:12)," KnoWhy 382 (November 16, 2017).