"Just be strong and very courageous to observe and do in accordance with all of the Torah that Moses My servant has commanded you. Do not stray therefrom right or left, in order that you succeed wherever you go. This book of the Torah shall not leave your mouth; you shall meditate therein day and night, in order that you observe to do all that is written in it, for then will you succeed in all your ways and then will you prosper."
Joshua 1:7-8