# Your ears will hear

"You will hear" 

# a word behind you saying

"him speaking behind you saying"

# This is the way, walk in it

To obey Yahweh is spoken of as if it were a person walking on his path. 

# when you turn to the right or when you turn to the left

Disobeying Yahweh is spoken of as if the person turned left or right off of Yahweh's path.