What is "Ka'asher Dibru Lahem ha'Nesi'im"?
Malbim: This is like they said initially "Ulai b'Kirbi Atah Yoshev v'Eich Echras Lecha Vris"? "Ish Yisrael" said this; surely it was the Nesi'im.
Why does it say "va'Yihyu" in the past tense?
Malbim: This was automatic. The Nesi'im has said "Ulai b'Kirbi Atah Yoshev"; if this is true, you must accept taxes and servitude.