Achish gave him Ziklag - Ziklag was at first given to the tribe of Judah, but afterwards it was ceded to that of Simeon, Joshua 15:31; Joshua 19:5. The Philistines had, however, made themselves masters of it, and held it to the time here mentioned; it then fell into the tribe of Judah again, and continued to be the property of the kings of Judah. This verse is a proof that this book was written long after the days of Samuel, and that it was formed by a later hand, out of materials which had been collected by a contemporary author. See the preface.
Ziklag - This was properly one of the cities of Simeon within the tribe of Judah (marginal references), but it had been taken possession of by the Philistines. The exact situation of it is uncertain.
Unto this day - This phrase, coupled with the title the kings of Judah, implies that this was written after the revolt of Jeroboam, and before the Babylonian captivity.