Genesis 49:5

5. Simeon and Levi are named together, because they were brothers in the twofold sense of being sons of the same mother, and so much alike in disposition and character . Hence, after pronouncing their names, the patriarch pauses, and then emphatically adds the word brothers. Their similar spirit was seen and became historical in their cruel slaughter of the Shechemites, (Genesis 34:25-31,) for in that massacre they led the way . The memory and fear of that act never departed from Jacob’s soul, and as Reuben’s incest cost him the rights and glory of the firstborn, so the bloody deed of Simeon and Levi colours all this oracle, and brought them cursing where they might have had blessing .

Instruments of violence their swords The word מכרת , rendered swords, occurs here only, and manifestly means some instrument of violence; but its derivation is uncertain. The ancient versions differ widely, and the word has been variously explained, as machinations, ( De Dieu,) betrothals, ( Dathe,) habitations, (Eng. version.) But the rendering swords, (perhaps from כור , to pierce, or penetrate,) seems most in harmony with the context, and is adopted by many of the best interpreters . According to Rashi, the Greek word μαχαιρα , sword, was derived from this . According to Gesenius, Rabbi Eliezer says: “Jacob cursed their swords in the Greek tongue . ” According to Genesis 34:25, Simeon and Levi “took each man his sword” ( חרב ) and slaughtered all the men of Shechem .