1 Chronicles 23:1-23, 6:16-30, 23:24-24:31

David was old. He made Solomon king.  Then he counted and blessed the different tribes and gave the Levites new duties concerning the temple to be built.  There were many more heads of families now and they drew lots to determine rank and order of service. 

24:31 "Families of the oldest brother were treated the same as the youngest."  This is important.  So often, the oldest son gets special rights and privileges, but in this instance there was no favoritism shown.  I am certain there were some hard feeling - especially among the oldest sons.  But David showed that all sons mattered equally to God.