2 Samuel 15:18

And all his servants passed on beside him; and all the Cherethites, and all the Pelethites, and all the Gittites, six hundred men which came after him from Gath, passed on before the king.

All the Cherethites, and all the Pelethites, х ha-Kªreetiy (H3774) wªkaal (H3605) ha-Pªleetiy (H6432)] - executioners and couriers; the designation of a part of David's body-guards [sooma to fulakes: Josephus, 'Antiquities,' b. 7:, ch. 5:, sec. 4], whose duty it was both to execute punishment and to convey the king's commands as speedily as possible to his officers, (Gesenius) (see the notes at 2 Samuel 8:18, etc.) [The Septuagint and Vatican; pas Chelethi kai pas ho Felethi; Alexandrine, pas ho Chereththei kai pas ho Feleththei.]

All the Gittites, six hundred men. These were a body of foreign guards, natives of Gath, whom David, when in the country of the Philistines, had enlisted in his service, and kept around his person. Addressing their commander, Ittai (who, according to Jewish tradition, was the son of Achish, king of Gath), he made a searching trial of their fidelity in bidding them (2 Samuel 15:19) abide with the new king.