Parallel
2 Samuel 3:6
King James Version (1769 Blayney revision, with Apocrypha) · Berean Standard Bible
And it came to pass, while there was war between the house of Saul and the house of David, that Abner made himself strong for the house of Saul.
During the war between the house of Saul and the house of David, Abner had continued to strengthen his position in the house of Saul.