4 David and all Israel went to Jerusalem (it was the old Jebus, where the Jebusites lived). 5 The citizens of Jebus told David, "No trespassing - you can't come here." David came on anyway and captured the fortress of Zion, the City of David. 6 David had said, "The first person to kill a Jebusite will be commander-in-chief." Joab son of Zeruiah was the first; and he became the chief.
Matthew Henry's Commentary on 1 Chronicles 11:4-6
Commentary on 1 Chronicles 11:1-9
(Read 1 Chronicles 11:1-9)
David was brought to possess the throne of Israel after he had reigned seven years in Hebron, over Judah only. God's counsels will be fulfilled at last, whatever difficulties lie in the way. The way to be truly great, is to be really useful, to devote all our talents to the Lord.