Meaning: Second Law
Deuteronomy is Moses's retelling of the Mosaic Law to Israel. Those ready to enter the promised land were either children or were not even born when the law was originally given at Mount Sinai.
In Deuteronomy 1, Moses is remembering/sharing the journey of Israel from Mount Sinai to Kadesh Barnea.
The Lord your God hath multiplied you, and, behold, ye are this day as the stars of heaven for multitude. (The Lord God of your fathers make you a thousand times so many more as ye are, and bless you, as he hath promised you!)
Then I said unto you Dread not, neither be afraid of them. The Lord your God which goeth before you, he shall fight for you, according to all the he did for you in Egypt before your eyes.