Genesis 34:25-29

And it came to pass on the third day, when they were sore, that two of the sons of Jacob, Simeon and Levi, Dinah's brethren, took each man his sword, and came upon the city boldly, and slew all the males.

On the third day, ... That period is critical, especially with adults, as fever generally ensues, with a total prostration of physical energy. That time, therefore, was chosen by the sons of Jacob for their meditated revenge, in the gratification of which they seem to have broken loose from every restraint, and to have allowed the wild spirit of Oriental ferocity to take as extensive a range, as is exemplified by the most ruthless allowed the wild spirit of Oriental ferocity to take as extensive a range, as is exemplified by the most ruthless Arabs in the present day.

Came upon the city - i:e., fell perfidiously upon the unsuspecting and disabled inhabitants.

Verse 27. The sons of Jacob came upon the slain, ... There is no evidence for regarding Genesis 34:27-29 as an interpolation; because although there is no copulative in our present Hebrew text, there must have been formerly, as the Septuagint has it as: [hoi de huioi, etc.]. Nor is there any ground for supposing that, after the massacre had been completed, the other sons of Jacob joined the homicides in the plundering of the city. Simeon and Levi (Genesis 34:25) were the perpetrators of this consummate act of villany; but they were undoubtedly assisted by a body of their servants, as Knobel in his commentary distinctly asserts must be assumed.