1 Chronicles 11:1 After King Saul and his three sons died – “then all of Israel gathered to David at Hebron.”
  Those men who came acknowledged they were family.

1 Chronicles 11:2 They recalled that even when Saul was alive and king, it was David who led the nation and that God said to you, ‘You shall shepherd My people Israel, and you shall be prince over My people Israel.”

  David was God’s shepherd and king to His people.
  David was a foreshadowing or “type” of Messiah.
  Messiah, God’s anointed One, would be Shepherd and King over all believer’s in Christ as their Savior.

1 Chronicles 11:3 In the days of David – the elders, the leaders of Israel purposely came before the LORD and to King David in Hebron and there David made a covenant with those leaders in Hebron [there they anointed David King over all Israel].
  Those men purposely chose to do everything according to the word of the LORD.

Consider this  ~

Do all you do
“according to the word of the LORD.”
1 Chronicles 11:3