If you count the years between King Benjamin’s speech in Mosiah 2–6 and Alma’s speech in Alma 5, there were 42 years, which makes the year of the speech, not so coincidentally, to be the sixth Sabbatical year after Mosiah had become king, then ruled for 33 years (Mosiah 29:46), and Alma then spoke at the beginning of the 9th year of the reign of judges (Alma 4:11, 20). The ancient Israelites had not only the seven-day week, but they had a seven-year cycle for agricultural purposes and also for covenant renewal. At the end of Deuteronomy in 31:10–11, one of the last things Moses said to the children of Israel was that once every seven years they needed to gather all the men, women, and children, in a Feast of the Tabernacles, "in which thou shalt read this law before all Israel in their hearing." So, the ninth year of the judges was year 42 from Benjamin’s Speech, which itself may have been given during a sabbatical or jubilee year. Thus, Alma and his people would have been observing a covenant renewal, hearing the law and reflecting again on how they could best be keeping their obligations as God’s covenant people. And so, Alma’s great speech was most likely given on a special occasion.
Appropriately, Alma gave this in Zarahemla, the same place where Benjamin had given his covenant speech as well. Many of the themes found in Benjamin’s speech are right here in Alma 5 too. The few themes that are not here have been superseded by the fact that they have a new regime of government, and Alma is speaking as the High Priest, not as the Chief Judge, let alone as a king. The setting of Alma 5 also must have included the seating of the new Chief Judge, Nephihah. We do not hear his inaugural speech. He must have accepted the responsibility, and the voice of the people would have sustained that action, and thus some ceremonies were probably involved. But all that we hear of that occasion are the words of Alma. After all, it is Alma’s book that we have, and this is Alma’s record of his own words. Covenant renewal was on his mind, and there had been no more powerful, prophetic, and governmental manifesto in Nephite history than Benjamin’s speech. It is alluded to here as the basis of the Nephites’ understanding of their covenant obligations, their theology, and their understanding of themselves, individually and as a people.
Ed J. Pinegar and John W. Welch, Experiencing a Mighty Change of Heart: Alma’s Guide to a Deep, Lasting Conversion (American Fork, UT: Covenant Communications, 2020), 3: "Because the Book of Mormon tells us the original setting and purpose of this speech, we can confidently understand and interpret its words in context. It is not a philosophical discourse. It is not an esoteric or abstract treatise. It was delivered as ecclesiastic instruction from the highest priesthood leader of the Church. It was aimed at unifying and regulating the whole body of the Church by inspiring and enabling the righteousness and worthiness of each individual member. It is through that lens that Alma 5 can most authentically and effectively be read and applied today."
Szink, Terrence L., and John W. Welch. "King Benjamin’s Speech in the Context of Ancient Israelite Festivals." In King Benjamin’s Speech: "That Ye May Learn Wisdom", edited by John W. Welch and Stephen D. Ricks, 147–223. Provo, UT: Foundation for Ancient Research and Mormon Studies, 1998.