1)
Why will Beis Yisrael not want to hear you?
1.
Radak: It is because "they do not want to hear Me." They despise My words and rebuke; they do not despise you.
2.
Malbim: It is not because they do not understand your language. Rather, "they do not want to hear Me." They say an excuse, that they do not understand the Navi's language.
2)
Who are "Chizkei Metzach"?
1.
Malbim: They contradict proofs via audacity.
3)
Who are "Keshei Lev"?
1.
Malbim: They do not fear punishments planned for them, based on the Navi's words.
