1)
Why is it written va'Yavu, and we pronounce it va'Yaku?
1.
Radak: Perhaps the Vov at the end of the Kesiv is in place of an Aleph; it means, [Yisrael] came [to the city], i.e. in every city; they fled to escape Yisrael.
2)
Why does it say "va'Yaku Vah" (singular)?
1.
Radak: Tradition teaches that this is one of two verses in which Bah means Bam (plural). The other is "v'Sirosh Yechachesh Bah" (Hoshe'a 9:2).
2.
Malbim: They struck [Mo'av] in the Medinah (city-state).
3)
Why does it say "v'Hakos Es Mo'av"?
1.
Malbim: They did so constantly.
