This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success.
Joshua 1:6 Be strong and of a good courage: for unto this people shalt thou divide for an inheritance the land, which I sware unto their fathers to give them.
Joshua 1:7 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.
Joshua 1:8 This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success.
Joshua 1:9 Have not I commanded thee? Be strong and of a good courage; be not afraid, neither be thou dismayed: for the LORD thy God is with thee whithersoever thou goest.
Joshua 1:10 Then Joshua commanded the officers of the people, saying,
The verse centers on "book", "shall", "depart", "mouth", "thou", "shalt", "meditate", and "therein". It is saying that the verse draws attention to "book" and "shall", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 7's "Only be thou strong and very courageous..." into verse 9's "Have not I commanded thee Be strong...", so "book" and "shall" belong inside that flow. In Joshua context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "book" and "shall" with trust shaped by these words, not by a vague optimism outside the passage.