The charge of the Lord thy God, i.e. what God hath charged or commanded thee to do; the act being put for the object; as is usual. In the law of Moses; which the prince was enjoined to transcribe and read, Deuteronomy 17:18, that he might govern his own and his people's actions by it. That thou mayest prosper; or, behave thyself prudently; for the word signifies both. Hereby he intimates that religion is the truest reason of state, and that all true wisdom and good success depends upon piety.
Related Commentaries of 1 Kings 2:3
1 Kings 2:3
3 And keep the charge of the LORD thy God, to walk in his ways, to keep his statutes, and his commandments, and his judgments, and his testimonies, as it is written in the law of Moses, that thou mayest prospera in all that thou doest, and whithersoever thou turnest thyself: