King James Version
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.English Standard Version
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 prosperous, and then you will have good success.New International Version
Do not let this Book of the Law depart from your mouth; meditate on it day and night, so that you may be careful to do everything written in it. Then you will be prosperous and successful.