In Moshe’s parting words to the nation, having dispensed his duties, he informs them how they need to face their responsibilities:
ה אֱלֹהֶיךָ הוּא עֹבֵר לְפָנֶיךָ, הוּא-יַשְׁמִיד אֶת-הַגּוֹיִם הָאֵלֶּה – Hashem, your God; He will cross you over, He will destroy the nations before you. (31:3)
The repeated emphasis on הוּא, that “He” will do it, seems strange. Why not just describe how God would take care of them in general?
The Ohr HaChaim explains that the Jews were worried that by losing Moshe, they would lose two advantages; first, that he could and would intercede on their behalf if they erred, such as with the Golden Calf, where his prayer ended the plague and prevented their annihilation; and second, that he would not be leading them in the wars they would inevitably fight on entry into the Land of Israel. They did not (could not?) lose a war with Moshe at the helm.
Moshe addressed the first concern by telling them that they were misplacing their trust – it had never been about him. הוּא עֹבֵר לְפָנֶיךָ – the same word used to describe Hashem’s characteristic of forgiveness – עובר על פשע. Moshe explained that in reality, it had been Hashem all along, that He had planted the idea of praying for the Jews in Moshe, and that the desire to forgive would remain. Moshe had simply been a tool for forgiveness, and not the root cause.
Regarding the concern of losing battles, Moshe expressed the same idea – it had never been him leading them to victory – הוּא-יַשְׁמִיד אֶת-הַגּוֹיִם הָאֵלֶּה – Hashem had been with them all the time, and would remain so evermore. They didn’t win wars because of Moshe, but because Hashem was orchestrating events.
Perhaps it also sheds light on the law that an army preparing for war did not enlist men who were frightened to fight. Someone who has done all they can to train and prepare must have proper faith in God – fear indicates a lack of belief, and such people cannot take up arms in His name.
The Seforno explains that the whole speech conveys this critical message – that they ought not get caught up in the medium. Hashem supervises and controls everything, and wanting a conduit is dangerous, and in parentheses, possibly idolatrous – this was precisely the rationale behind the Golden Calf. Moshe emphasised that every person alone has a relationship with Hashem, and that intermediaries are not valid representatives for the people themselves.
R Tzadok HaCohen notes how the whole Sefer Devarim – Moshe’s entire speech – can be read as speaking directly to the reader.
Teachers and guides are critically important influences – the Mishna in Avos requires it of us. But living vicariously through a proxy is something else entirely. Moshe was telling the Jews that after 40 years of maturation, they were finally ready to become what they left Egypt to be.
Eventually, the training wheels have to come off.