As David prepared himself to die (of old age), he gave his son some advice:
1 Kings 2:2-4 I am going where everyone on earth must someday go. Take courage and be a man.
So how does one ‘be a man’?
1 Kings 2:3 Observe the requirements of the Lord your God, and follow all his ways. Keep the decrees, commands, regulations, and laws written in the Law of Moses …
And the benefits?
1 Kings 2:3-4 … so that you will be successful in all you do and wherever you go. If you do this, then the Lord will keep the promise he made to me. He told me, ‘If your descendants live as they should and follow me faithfully with all their heart and soul, one of them will always sit on the throne of Israel.’