John Wesley on Genesis 49:7

Cursed be their anger - Not their persons. We ought always in the expressions of our zeal carefully to distinguish between the sinner and the sin, so as not to love or bless the sin for the sake of the person, nor to hate or curse the person for the sake of the sin. I will divide them - The Levites were scattered throughout all the tribes, and Simeon's lot lay not together, and was so strait that many of that tribe were forced to disperse themselves in quest of settlements and subsistence. This curse was afterwards turned into a blessing to the Levites; but the Simeonites, for Zimri's sin, Num 25:6 - 14, had it bound on.