Joab followed the example of Adonijab (margin reference). The tabernacle was now at Gibeon 1 Kings 3:4; 1 Chronicles 16:39.
Related Commentaries of 1 Kings 2:28
1 Kings 2:28
28 Then tidings came to Joab: for Joab had turned after Adonijah, though he turned not after Absalom. And Joab fled unto the tabernacle of the LORD, and caught hold on the horns of the altar.