1 Samuel 17:4

4. A champion The Septuagint has, a mighty man; Vulgate, bastard; Syriac and Arabic, a giant. But the Hebrew, אישׁ הבנים , literally signifies a man between the two; that is, an arbitrator between the two armies, or one who was lord of the space between the two camps. Goliath, the pride of the Philistine hosts, stepped forth between the two armies and proposed by a personal contest with a chosen warrior from the Israelites, and according to the conditions stated in 1 Samuel 17:9, to decide the fortunes of the war. Such single combats at the head of armies were not unusual in ancient times, as is witnessed by the combats of Paris and Menelaus. (Homer, Iliad, book 3.)

Of Gath And therefore probably a remnant of the Anakim that escaped the sword of Joshua. Joshua 11:22.

Whose height… six cubits and a span That is, if we reckon the cubit at twenty-one inches, about ten and one half feet. Josephus (“Antiquities,” 1 Samuel 18:4-5) mentions one Eleazar, a Jew by birth, whose height was seven cubits; and Pliny speaks of a giant Pusio, whose height exceeded ten Roman feet.