How do you cast off sins?
Radak: Regret them, and you cast off from you your punishment.
Malbim: If you do not repent amidst love, at least cast off the heavy burden of Pesha (sins or rebellion). Via Teshuvah amidst fear, Mezid becomes like Shogeg.
What is "Lev Chadash v'Ru'ach Chadashah"?
Malbim: It is new choice. The heart is the power that rules in man. The Ru'ach puts images on the heart. Until now it put evil images for all sins, and the heart ruled with its choice to do evil. Now strive that the Ru'ach will put on the heart only good images of Torah, Avodah and Yir'as Hashem, and the heart will rule the entire day with fear.
Why does it say "v'Lamu Samusu Beis Yisrael"?
Malbim: Why should you die? Repent, so you will not die! Even Teshuvah amidst fear will be accepted, for two reasons (refer to 18:32:1:2).
