Joshua 1:8

8 The book of this law depart not from thy mouth, but thou shalt think therein in days and nights, that thou keep and do all things that be written therein; then thou shalt (ad)dress thy way, and thou shalt understand it. (Let not this Book of the Law depart from thy mouth, but think thou on it day and night, so that thou obey and do all the things that be written in it; then thou shalt make thy way prosperous, and be successful.)

Joshua 1:8 Meaning and Commentary

Joshua 1:8

This book of the law shall not depart out of thy mouth
He was often to read it, frequently repeat it, and speak of it, to refresh his own memory with it, and the memory of those about him. Jarchi restrains it to the book of Deuteronomy now before him:

but thou shalt meditate therein day and night;
whenever he had any leisure from the important business of his office, whether by day or night, see ( Psalms 1:2 ) ;

that thou mayest observe to do according to all that is written
therein;
which frequent speaking of it, and constant meditation on it, would lead unto:

for then thou shalt make thy way prosperous, and then thou shalt have
good success;
in his wars with the Canaanites.

Joshua 1:8 In-Context

6 Be thou comforted, and be thou strong; for thou shalt part by lot to this people the land, for which I swore to thy fathers, that I should give it to them. (Be thou encouraged, and be thou strong; for thou shalt divide up by lot the land to this people, which I swore to thy fathers, that I would give them.)

7 Therefore be thou comforted, and be thou full strong, that thou keep and do all the law, which Moses, my servant, commanded to thee; bow thou not from it to the right side, either to the left side, that thou understand all things which thou doest. (And so be thou encouraged, and be thou strong, so that thou obey and do all the law, which my servant Moses commanded to thee; turn thou not from it to the right, or to the left, so that thou shalt prosper in all things wherever thou goest.)

8 The book of this law depart not from thy mouth, but thou shalt think therein in days and nights, that thou keep and do all things that be written therein; then thou shalt (ad)dress thy way, and thou shalt understand it. (Let not this Book of the Law depart from thy mouth, but think thou on it day and night, so that thou obey and do all the things that be written in it; then thou shalt make thy way prosperous, and be successful.)

9 Lo! I command to thee; be thou comforted, and be thou strong; do not thou dread, nor be thou afeared; for thy Lord God is with thee in all things, to which thou goest. (Lo! I command thee; be thou encouraged, and be thou strong; do not thou fear, nor be thou afraid; for the Lord thy God is with thee in all things, to which thou goest.)

10 And Joshua commanded to the princes of the people, and said, (And Joshua commanded to the leaders of the people, and said,)