Genesis 49:7 - Matthew Poole's English Annotations on the Holy Bible

Cursed be their anger, or, cursed was. It was execrable and abominable both before God and men; such as deserved and brought the curse of God upon themselves, which I, as God's instrument, am now to pronounce against them. I do here declare, in the name of God, that they shall be divided and dispersed in Jacob, & c.; that is, among the children or tribes of Jacob or Israel. Prophets are said to do what they foretell that God will do, as Jeremiah is said to root out and pull down kingdoms, Jeremiah 1:10, and Ezekiel to destroy the city, Ezekiel 43:3. Add Hosea 6:5. Note here how suitable their punishment was to their crime. They sinned by conspiracy and confederation in the counsel and action, and they are punished with division or separation, not only of the two brethren and their tribes, but of the children and families of the several tribes, one from another. This was eminently fulfilled in the tribe of Levi, which had no proper portion or inheritance, but was scattered among all the tribes, Joshua 18:7, though afterwards God turned this curse into a blessing. And for Simeon, he had no part of his own in the division of the land; but the portion of Judah being too large for that tribe, he was taken into that lot, and was as an inmate to them, Joshua 19:1,2,9, and afterwards part of them were forced to seek new seats, and so were divided from the rest of their brethren, 1 Chronicles 4:27,39,42. And moreover, the Jewish doctors write, that that tribe was so straitened in their habitations and conveniences, that a very great number of them were forced to scatter themselves amongst the other tribes to get a subsistence by teaching their children.