But most importantly, we see several critical shifts in language and action -- and in God's response. B'nei Yisorel are being made into the singular Yisroel. Moshe gradually retreats as the active leader and Yisroel takes the lead. God likewise moves from the obviously miraculous (summoning the water) to the more derech hateva (the plague of poisonous snakes). Yisroel display a heightened perception in recognizing the snakes -- which could be attributed to nature and be used as further evidence that Moshe and God had led Yisroel out to die -- as punishment from God. It is not only that they recognize and do initial teshuva by asking Moshe to intervene, but the cure itself depends on their personal teshuva and relationship with God rather than simply on Moshe's intercession (albeit they are still training and still need an intermediary).
Similarly, Yisroel move to active and derech ha teva in their dealings with the surrounding nations. We begin with Moshe sending messengers to the King of Edom. But midway through it shifts to Yisroel (using singular) and Edom (also using singular) (reading the layning really brings home the textual shift). Similarly, when the nation is attacked and captives taken, it is Yisroel (not Moshe) that takes initiative, asking God to give the enemies into their hands.
In this, we may also explain two puzzling features. The poem and the reference to the book "The Wars of God." These poems are unusual in that they are not attributed to God or to prophecy. Nor is the Book of the Wars of God given an author or a holy or prophetic status. Rather, we must conclude that these poems and the The Wars of God are products of national authors and poets writing their own songs of praise and their own history. As with other works of man, they do not last. But they are a critically important transition in that they represent a spontaneous move to record their own history and celebrate their victories.
They are mentioned, therefore, not for their own sake, but for what they represent -- a sign of emotional growth. L'mah ha davar domeh? (To what may we compare this?) Every parent has a collection of things made by their child at various stages of life. Though of objectively little worth, these items become precious keepsakes for the parent. And not only for the parent. At times the when the child grows and is distant or disobedient, the parent may look at these keepsakes and remember the young child and recall the love and affection that seems absent today. At other times, when the parent and child have reconciled, the keepsakes have meaning to bond them together. And when the parent is gone, the child may keep the items as beloved keepsakes of the parent. "My parents kept this thing because they loved me."
So too the poems of Chukot and the reference to the Book of the War of God. God most lovingly records this stage of our national development and preserved it forever in the Torah. In times of our disobedience, God remembers the love and difficulty of raising the young nation. "Zacharti lach chessed n'uriach." ("I am reminded of the happiness of our youthful love" Jeremiah 2:1) In our exile, we recall when God was pleased to record our every victory and expression. In the days of the Messiah, we shall dwell again in the house of the Lord and we shall recall jointly with love the time of our youth.