John Gill Commentary 1 Chronicles 12:1

"Now these are they that came to David to Ziklag, while he yet kept himself close because of Saul the son of Kish; and they were among the mighty men, his helpers in war." — 1 Chronicles 12:1 (ASV)

Now these are they that came to David to Ziklag Given him by Achish to live in, when he fled from Saul, (1 Samuel 27:6).

while he yet kept himself close, because of Saul the son of Kish ; when he was an exile from his own country, and obliged to live retired in a foreign one, because of Saul's persecution of him, and seeking to take away his life:

and they were among the mighty men, helpers of the war ; not against Saul, with whom David had none, but with the Amalekites, and others, (1 Samuel 27:8) (1 Samuel 30:16 1 Samuel 30:17).