C. F. Keil and Franz Delitzsch on Judges 3:16

Jdg 3:16

Ehud availed himself of the opportunity to approach the king of the Moabites and put him to death, and thus to shake off the yoke of the Moabites from his nation. To this end he provided himself with a sword, which had two edges (פּיות from פּה, like שׂיו, Deu 22:1, from שׂה), a cubit long (גּמר, ἁπ. λεγ., signified primarily a staff, here a cubit, according to the Syriac and Arabic; not “a span,” σπιθαμή, lxx), and “did gird it under his raiment upon his right thigh.”