7 Only be thou strong and very courageous, that thou mayest observe to do according to all the law, which Moses my servant commanded thee: turn not from it to the right hand or to the left, that thou mayest prosper  whithersoever thou goest.
7 "Be strong and very courageous. Be careful to obey all the law my servant Moses gave you; do not turn from it to the right or to the left, that you may be successful wherever you go.
7 Only be strong and very courageous, being careful to do according to all the law that Moses my servant commanded you. Do not turn from it to the right hand or to the left, that you may have good success
7 Give it everything you have, heart and soul. Make sure you carry out The Revelation that Moses commanded you, every bit of it. Don't get off track, either left or right, so as to make sure you get to where you're going.
7 Only be strong and very courageous, that you may observe to do according to all the law which Moses My servant commanded you; do not turn from it to the right hand or to the left, that you may prosper wherever you go.
7 Be strong and very courageous. Be careful to obey all the instructions Moses gave you. Do not deviate from them, turning either to the right or to the left. Then you will be successful in everything you do.
Matthew Henry's Commentary on Joshua 1:7
Commentary on Joshua 1:5-9
(Read Joshua 1:5-9)
Joshua is to make the law of God his rule. He is charged to meditate therein day and night, that he might understand it. Whatever affairs of this world we have to mind, we must not neglect the one thing needful. All his orders to the people, and his judgments, must be according to the law of God. Joshua must himself be under command; no man's dignity or dominion sets him above the law of God. He is to encourage himself with the promise and presence of God. Let not the sense of thine own infirmities dishearten thee; God is all-sufficient. I have commanded, called, and commissioned thee to do it, and will be sure to bear thee out in it. When we are in the way of duty, we have reason to be strong and very bold. Our Lord Jesus, as Joshua here, was borne up under his sufferings by a regard to the will of God, and the commandment from his Father.