Joshua 1:7

Only be strong and very courageous {to observe diligently the whole law} that Moses my servant commanded you. Do not turn aside from it, [to] the right or left, so that you may succeed {wherever you go}.

Deuteronomy 5:32

"[So] you must be careful to do [just] as Yahweh your God commanded you; you shall not turn [to the] right or [to the] left.

Deuteronomy 28:14

And you [shall] not turn aside from {any of} the words that I [am] commanding you {today} [to the] right or left by going after other gods to serve them.

Joshua 11:15

Just as Yahweh commanded Moses his servant, so Moses commanded Joshua, and Joshua did; he left nothing undone that Yahweh had commanded Moses.

Deuteronomy 29:9

And {you must diligently observe the words of this covenant}, so that you may succeed in all that you do.

Numbers 27:23

And he placed his hands on him and {commissioned him} just as Yahweh spoke by the hand of Moses.

Deuteronomy 12:32

All of the things that I [am] commanding you, {you must diligently observe}; you shall not add to it, and you shall not take away from it."

Deuteronomy 31:7

Then Moses summoned Joshua, and he said to him {in the presence of all Israel}, "Be strong and be courageous, for you will go with this people into the land that Yahweh swore to their ancestors to give to them, and you will give it to them as an inheritance.

Joshua 1:1

After the death of Moses the servant of Yahweh, Yahweh said to Joshua son of Nun, the assistant of Moses, saying,

Joshua 1:8

The scroll of this law will not depart from your mouth; you will meditate on it day and night so that {you may observe diligently all that is written} in it. For then you will succeed [in] your ways and prosper.

1 Kings 2:3

You shall keep the charge of Yahweh your God, to walk in his ways, to keep his statutes, his commandments, his judgments, and his testimonies, as are written in the law of Moses, so that you may prosper in all that you do and everywhere you turn,

1 Chronicles 22:13

Then you will prosper if you take care to do the statutes and judgments which Yahweh commanded Moses concerning Israel. Be strong and be courageous; fear not and do not be dismayed.

Proverbs 4:27

Do not swerve right or left; remove your foot from evil.

Proverbs 8:20

In the way of righteousness I walk, in the midst of paths of justice,

Treasury of Scripture Knowledge

Summary

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.

Bible References

Which moses

Joshua 1:1
After the death of Moses the servant of Yahweh, Yahweh said to Joshua son of Nun, the assistant of Moses, saying,
Joshua 11:15
Just as Yahweh commanded Moses his servant, so Moses commanded Joshua, and Joshua did; he left nothing undone that Yahweh had commanded Moses.
Numbers 27:23
And he placed his hands on him and {commissioned him} just as Yahweh spoke by the hand of Moses.
Deuteronomy 31:7
Then Moses summoned Joshua, and he said to him {in the presence of all Israel}, "Be strong and be courageous, for you will go with this people into the land that Yahweh swore to their ancestors to give to them, and you will give it to them as an inheritance.

Turn not

Deuteronomy 5:32
"[So] you must be careful to do [just] as Yahweh your God commanded you; you shall not turn [to the] right or [to the] left.
Deuteronomy 12:32
All of the things that I [am] commanding you, {you must diligently observe}; you shall not add to it, and you shall not take away from it."
Deuteronomy 28:14
And you [shall] not turn aside from {any of} the words that I [am] commanding you {today} [to the] right or left by going after other gods to serve them.
Proverbs 4:27
Do not swerve right or left; remove your foot from evil.
Proverbs 8:20
In the way of righteousness I walk, in the midst of paths of justice,

That

Deuteronomy 29:9
And {you must diligently observe the words of this covenant}, so that you may succeed in all that you do.
1 Kings 2:3
You shall keep the charge of Yahweh your God, to walk in his ways, to keep his statutes, his commandments, his judgments, and his testimonies, as are written in the law of Moses, so that you may prosper in all that you do and everywhere you turn,
1 Chronicles 22:13
Then you will prosper if you take care to do the statutes and judgments which Yahweh commanded Moses concerning Israel. Be strong and be courageous; fear not and do not be dismayed.

General references

Deuteronomy 4:2
You must not add to the word that I [am] commanding you, and you shall not take away from it [in order] to keep the commands of Yahweh your God that I [am] commanding you [to observe].
Deuteronomy 15:5
If only you listen well to the voice of Yahweh your God {by observing diligently} all of these commandments that I [am] commanding you {today}.
Deuteronomy 29:9
And {you must diligently observe the words of this covenant}, so that you may succeed in all that you do.
Joshua 10:8
And Yahweh said to Joshua, "Do not be afraid of them, for I have given them into your hand; {no one will withstand you}.
Psalm 119:4
You have commanded your precepts, that [we] should keep [them] diligently.