This book of the law shall not depart from your mouth, but you shall meditate on it day and night, so that you may be careful to do according to all that is written in it; for then you will make your way successful, and then you will be prosperous.
Joshua 1:6 Be strong and courageous, for you shall cause this people to inherit the land which I swore to their fathers to give them.
Joshua 1:7 Only be strong and very courageous to be careful to do according to all the law which Moses My servant commanded you; do not turn aside from it to the right or to the left, so that you may be prosperous wherever you go.
Joshua 1:8 This book of the law shall not depart from your mouth, but you shall meditate on it day and night, so that you may be careful to do according to all that is written in it; for then you will make your way successful, and then you will be prosperous.
Joshua 1:9 Have I not commanded you? Be strong and courageous! Do not be in dread or be dismayed, for Yahweh your God is with you wherever you go.”
Joshua 1:10 Then Joshua commanded the officers of the people, saying,
The verse centers on "book", "shall", "depart", "mouth", "meditate", "night", and "careful". 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 strong and very courageous to..." into verse 9's "Have I not commanded you 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.