First Kings chapter 2.
I wondered why Adonijah was killed for asking to marry Abishag and so I looked up a commentary which basically said Adonijah was still trying to be deceitful even though he claims he came in peace to Bethsheba. Abishag is the woman who lay with King David to keep him warm and she nursed him. In the eyes of Israel it was assumed she was a part of King David's concubine. For Adonijah to marry her would then give the impression that he was indeed a king since she was considered a part of King David's concubine. Solomon saw his deceit and immediately had him killed.
King David had final words on his death bed to the new King, Solomon. So they were therefore very valuable words. He wanted to make sure restitution was made.
My dad, on his deathbed with cancer, gathered all of us kids and daughter-in-laws and had each of us kids come into his bedroom and he shared his final words. One of the things he said to me was he regrets he didn't give his life to the Lord sooner. And he wanted me to give an altar call at his funeral service. So I did.
It's a reminder to me, we are on this Earth for a short time and sharing Christ is where it's at. Our life needs to be all about Jesus and all about sharing Jesus!