1 Chronicles 11:5 TLB

[5] But the people of Jebus refused to let them enter the city. So David captured the fortress of Zion, later called the City of David, and said to his men, "The first man to kill a Jebusite shall be made commander-in-chief!" Joab, the son of Zeruiah, was the first, so he became the general of David's army.