1)
Verse 4 said so! Why is this repeated?
1.
Radak: There is a small change here. Above it said "Derachayich"; here it says "ki'Drachayich 1 ." They mean the same. Also, here it adds ["Ki Ani Hashem] Makeh."
1
Malbim: "Ki'Drachayich" shows that the punishment will correspond to the sins and their measure. Via this you will recognize that the punishment is not via an intermediary, rather, "Ki Ani Hashem Makeh."
