1)
The previous verse said "ba'Yom ha'Hu". Why is this repeated?
1.
Malbim: Then, Mashi'ach ben Yosef will die in war.
2)
What is the meaning of "Avakesh Lehashmid"?
1.
Rashi: I will seek to eradicate them ? I will be meticulous about their sin,
2.
Rashi citing Avodah Zarah 4a: I will seek their merit, and examine the records of their deeds. If they have enough merits, I will leave them. If not, I will destroy them.
3.
Radak: I will seek and fulfill. I will put all my desire to eradicate them.
4.
Malbim: I will seek to eradicate all the Goyim for the sin of killing Mashi'ach ben Yosef.