Alma begins his final blessing to his son, Helaman, with two important lessons from history. The first is the Nephite promise of the land. This is the essential New World covenant between Jehovah and the Nephite people. We first saw it in 1 Nephi 4:14, then again in 2 Nephi 1:20; Jarom 1:9; Omni 1:6; Mosiah 1:7; 2:22 and 2:31. Other verses show the fulfillment of that covenant, both when the Nephites do prosper in the land, and when they do not because of transgression. Thus, the very first thing Alma declares to his son is the reiteration of the foundational principle of the Nephite nation and their covenant with Jehovah.
The second lesson is more personal. While Alma himself was not in physical captivity, he was in spiritual captivity. His father, Alma the Elder, was in physical bondage. Whether in spiritual or physical captivity, Alma reminds his son that his family’s experiences underscore the deliverance from such captivity. Thus, even in the occasion when the Nephites do not sufficiently keep the commandments in order that they may prosper in the land, even when they fall into captivity because of unrighteousness, all is not lost. Jehovah is still willing to live up to His part of the covenant, and deliver them upon the principle of repentance.
While the two verses appear to speak of different things, Alma would have seen them as related. The first verse was the promise of prosperity if they keep the commandments, and the second was the hope of repentance and deliverance should they not.