1)
What is the meaning of "ha'Al Elu Lo Efkod"?
1.
Radak citing Targum Yonasan: Will I not punish for these, to bring evil on them?!
2.
Malbim: This chapter discussed idolatry, Arayos and murder. First it discussed Arayos, and said "ha'Al Elu Lo Efkod" (verse 9). Then it discussed idolatry, and said "Hineni Mevi Aleichem Goy..." (verse 15). Now it discussed murder, and what its punishment will be.