1)
It already mentioned Chilul Shabbos (13). Why is this repeated?
1.
Radak: (12): It is because the Mitzvah of Shabbos is great, and is equated to all the Mitzvos.
2)
Does "Ki" give the reason?
1.
Malbim: The reason why they despised His Mishpatim was not due to desire and the Yetzer ha'Ra. Rather, heresy in their hearts pursues foreign Emunos and idols, and they do not believe in Hashem, like the Meraglim, who did not believe in Hashem's ability. This sin, which is due to denial, is far greater.
