David establishes temple musicians to provide perpetual worship of God. David then seeks out Saul’s last living relative, Mephibosheth, and gives him wealth in honor of his father and brother. David then goes to war after the Ammonites insult his ambassadors.
Erwin McManus at Mosaic in Los Angeles just preached a decent sermon that focused on David establishing the temple musicians. It was part of a sermon on using our strengths to honor God. The musicians were chosen because they were gifted in music; he makes his point in a much more profound way. You can find his sermon here (it is the “Release Your Potential” sermon).
Mephibosheth is an interesting character. If you remember he was cripples when his nurse dropped him while fleeing David’s army. Since that time Mephibosheth has been living with the knowledge that the king will probably have him killed since he is the sole heir of Saul. However, David chooses to echo the grace he has received from God by showing grace to Mephibosheth.
The story of the Ammonites gives an important clue as to carrying out a succesful diplomatic effort: don’t insult other countries ambassadors and send them home naked. Provocation is usually a poor diplomatic strategy.