Why does Mormon choose to place the translation of the plates found by Limhi’s people after the sons of Mosiah decline the kingship? The only indication that Mormon gives is that the people were anxious to know what was on the plates. While this is certainly true, it is not a complete answer.
Unfortunately, Mormon gives us no time frame for any of these events. We have no firm dating until Mosiah 29:45–6 which dates the deaths of both Alma1 and Mosiah 509 years after the departure from Jerusalem. To recount just a few important dates, the deaths of Alma1 and Mosiah would correlate to 92 B.C. Mosiah was crowned in 124 B.C., 462 Nephite years from the departure from Jerusalem. The reunification of the people of Alma1 and Limhi with the people of Zarahemla had to occur after Mosiah was made king—therefore somewhere between 124 B.C. and 92 B.C.
Thus, within this thirty-two-year span the creation of the church in Zarahemla and the conversion of Alma2 and the sons of Mosiah had taken place. Certainly the church would have been established within a year or so after reunification, which would have been a minimum of a year after the Limhites’ departure. Adding a couple of years for safety, we might estimate 120 B.C. as a reasonable date for the church’s establishment.
It does not appear from Mormon’s account that Alma1 and Mosiah died immediately after translating the records. Certainly Mosiah doesn’t appear to think that Alma1 is near death. He gave the records to Alma1 without any discussion of Alma1’s possible heirs. Nevertheless, these events had to occur somewhere near the end of his reign or he would not have been considering succession options. Placing the conversion of the sons of Alma1 and Mosiah near the end of this thirty-two-year period provides enough time for the church to be established, for them to decide to oppose it, and to have had some time to be successful.
This situation adds another wrinkle to the sons of Mosiah’s request to preach to the Lamanites. The journey would take some time; and no matter how successful or unsuccessful, Mosiah could not be sure that his sons would return speedily. It is perhaps because of their departure that Mosiah begins thinking about transferring the rule.
Mosiah, sons gone and having refused the throne, would know that the transfer of power might involve controversy and contention, a fear he acknowledges (Mosiah 29:7). This mention suggests that Mosiah is preparing for the worst-case scenario. First, he takes care of what he considers most important—the sacred records—by preparing to transfer them to Alma1’s custody for safekeeping. He probably hopes to keep them from becoming an element in a possible power struggle, even war, among the people of Zarahemla. His city suffered from ready-made fault lines along which his people could divide, given a contentious transfer of power.
Apparently one of the preparatory tasks he set himself was translating the record on the gold plates that the Limhites had found and turned over to Mosiah soon after their arrival in Zarahemla, since they were quite interested in their contents (Mosiah 8:9, 11–12). Clearly Mosiah had not translated them during the (as a rough guess) perhaps twenty years they had been in his care. Why he had delayed so long is not explained, but perhaps he understood that the new leader might lack the power to use the two stones. (What we call the Urim and Thummim are never called by that name in the Book of Mormon.)