Exodus 34:27-28

27) Then the LORD said to Moses, "Write down these words, for in accordance with these words I have made a covenant with you and with Israel." 28) So he was there with the LORD forty days and forty nights; he did not eat bread or drink water. And he wrote on the tablets the words of the covenant, the Ten Commandments.

Exodus 17:14

14) Then the LORD said to Moses, "Write this in a book as a memorial and recite it to Joshua, that I will utterly blot out the memory of Amalek from under heaven."

Joshua 1:7-8 - God speaking to Joshua

7) "Only be strong and very courageous; be careful to do according to all the law which Moses My servant commanded you; do not turn from it to the right or to the left, so that you may have success wherever you go. 8) "This book of the law shall not depart from your mouth, but you shall meditate on it day and night, so that you may be careful to do according to all that is written in it; for then you will make your way prosperous, and then you will have success.