Simeon and Levi are brethren— That is, fellows in wickedness. אחים achim, rendered brethren, is used for persons of the same turn of mind. See Proverbs 18:9; Proverbs 18:24. Jacob intimates that these his sons were not nearer related in blood than in their cruel disposition, which had manifested itself in an act shocking to humanity; on the mention of which, Proverbs 18:6 he immediately breaks off, declares in an affecting manner that he was not privy to, and testifies his utter abhorrence of it. He comes next to some of the particulars of that infamous day, when these two chiefs, in cold blood, destroyed a whole town, from the principal to the meanest inhabitant, (as is related at length, with all the circumstances of perfidy and inhumanity, ch. 34:) In Proverbs 18:7 the good old man, roused with indignation at so barbarous a scene, warmly exclaims against the immoderate wrath which had produced such bitter fruits, and takes his leave of them, by assuring them that their punishment, though flow, would certainly overtake them.
Instruments of cruelty, &c.— i.e.. Their swords were instruments of cruelty. They have abused their arms, by cruelly and deceitfully killing the innocent Shechemites. The Hebrew word מכרתיהם mekeroteihem, seems very naturally derived from כרת karet, to cut off as a branch, Isaiah 18:5 and so to signify instruments of cutting, swords, &c. and to justify the marginal translation of our English Bibles, weapons of violence.