And there was also a battle at Gath, where there was a man of great stature with six fingers on each hand and six toes on each foot—twenty-four in all. He too was descended from Rapha,
The Philistines were nearly subdued (Ch1 18:1); but, as in the destruction of the Canaanites by Joshua the sons of Anak were last subdued (Jos 11:21), so here in the conquest of the Philistines the giants of Gath were last brought down.
Commenting on 1 Chronicles 20:4-8
And yet again there was war at Gath, where was a man of [great] stature, whose fingers and toes [were] four and twenty, six [on each hand], and six [on each foot]: and he also was the son of the giant. (d) Meaning that he had six apiece on hands and feet.
Fingers and toes were four and twenty - See the note on Sa2 21:20.