# lay up these words of mine in your heart and soul

"be very careful to remember these words that I am saying to you" 

# these words of mine

"these commands that I have given you"

# your heart and soul

Here "heart" and "soul" represent a person's mind or thoughts. 

# bind them

"tie these words." See Deuteronomy 6:8.

# as a sign on your hand

"as something to make you remember my laws"

# let them be as frontlets between your eyes

"let my words be as as frontlets between your eyes."

# frontlets

ornaments a person wears on the forehead