David … took his sword: if readers may misunderstand and think that David took his own sword and killed Goliath with it, it may be wise to follow the model of Good News Translation and make explicit that he took “Goliath’s sword.” Later, when David is fleeing from Saul, he receives Goliath’s sword from the priest Ahimelech (21.9). Sword here and “javelin” in verse 6 are different Hebrew words, but both probably refer to the same thing. Sword here is a general term, while the word in verse 6 is probably a technical term for a specific kind of sword.

Sheath: the same Hebrew word is used elsewhere for a “razor” (Num 6.5; Psa 52.2), but here, as in 2 Sam 20.8, it refers to the covering or enclosure where a sword is kept when it is not needed for fighting. The sheath was probably made of leather, but ancient sheaths were sometimes made of wood, metal, and ivory. Goliath had apparently not drawn his sword out of its sheath by the time David hit him with the stone.

Here, as in verses 4 and 23 above, Revised Standard Version calls Goliath champion of the Philistines. However, the Hebrew terms are not the same. As noted above on verse 4, the Hebrew there should be rendered “infantryman,” while here in verse 51 the word refers to a man who is vigorous. The same term is rendered “strong” in 14.52.

Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on the First and Second Books of Samuel, Volume 1. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here .