A "cubit" is a unit of measurement equal to 46 centimeters. Alternate translation: "2.3 meters" (See: [[rc://en/ta/man/translate/translate-bdistance]])
This compares the size of the spear with the size of a weaver's beam. Alternate translation: "a spear the size of a weaver's beam" (See: [[rc://en/ta/man/translate/figs-explicit]])
"Benaiah went down to the Egyptian." This idiom means that he met him in battle. Alternate translation: "he attacked him" (See: [[rc://en/ta/man/translate/figs-idiom]])