LEFT-HANDED (אִטֵּ֖ר יַד־יָמִין). The word is used only twice in the Bible, in both cases of Benjaminites. In Judges 3:15 Ehud, son of Gera, who killed the king of Moab, Eglon, and thereby delivered Israel from the Moabites, is described as being left-handed. In Judges 20:16 it is said that the Benjaminites numbered 26,000 soldiers. of whom seven hundred were left-handed; “every one could sling a stone at a hair, and not miss.” The Heb. words suggest a man who for one reason or another uses his left hand instead of his right hand.

International Standard Bible Encyclopedia (1915)

The Hebrew presents a combination of words signifying literally, a man whose right hand is impeded or lame, who therefore uses the left hand instead, or one who by habit prefers the use of the left hand, where others use the right. It is interesting to note that in both instances, where the expression occurs in the Scripture, it refers to individuals belonging to the tribe of Benjamin (which name itself signifies "a son of the right hand"!). The first is Ehud, son of Gera, who killed Eglon, king of Moab, and thereby delivered Israel from paying tribute to the Moabites (Jud 3:15). The other instance is that of the 700 selected Benjamites, who, though lefthanded, "could sling stones at a hair-breadth, and not miss" (Jud 20:16; of 1Ch 12:2).