This tells us quite a bit about Nephite worship. This hosanna cry was something that they would perform as they approached the temple, as in Psalm 118. It represents a triumph, a victory in which the king is coming into his city and into the temple. It is perfectly suitable for this great victory celebration.
Notice also that this victory song talks about the God of Abraham, the God of Isaac, and the God of Jacob. The righteous Nephites are still very much involved with the covenant that God made with Abraham, Isaac, and Jacob, even this far into their history in the New World. This triad appears again in 3 Nephi 20—22, in which Jesus talks about the renewal of that covenant and its importance in the temple. In Leviticus 26, which is the conclusion and culmination of the whole book, God makes a promise to Israel. If Israel disobeyed, there would be curses. But no matter where they were, no matter how far away they went, no matter how removed from him they might become, he would never forget them, and he would never forget the covenant that he had made with “Jacob, Isaac, and Abraham” (Lev. 26:42). Notice that these three names appear here in Leviticus in the reverse order that is normally found. This text was used in one of the holiest moments in the ancient Israelite observance of their covenant renewal. It was a recognition of God’s promises to bless them, but also the consequences of their violating that covenant.
We can imagine how desperate the Nephites were. They may have thought they had won the war when Giddianhi was killed. However, when his follower Zemnarihah arose they had to go at it again. Because this was the second time the Lord delivered them, the Nephites responded with a really powerful expression of piety and worship. The next time the people shout “hosanna,” it will be at the Savior’s appearance in 3 Nephi 11.