1)
Why did he say "Sesom ha'Devarim"?
1.
Ibn Ezra: Seal the Sefer, so only one who is proper to see it will see it.
2.
Malbim: The Ketz is in the distant future. It is better that everyone think that it can come in his lifetime.
2)
Why does it say Yeshotetu?
1.
Ibn Ezra: They will roam to see Hashem's word.
3)
Why will Da'as increase?
1.
Malbim: It is known that the Ge'ulah must come before the seventh millennia. The closer it gets to then, the Safek [when it will be] is smaller, and knowledge [when it did not come] increases.
