Why does the Torah now insert the phrase "Eis Kol asher Tzivah Hashem aleichem ... "?
Rashi and Rashbam: To teach us that if someone acknowledges Avodah-Zarah, it is as if he denies the entire Torah.
Why does the Torah add "Min ha'Yom asher Tzivah Hashem ... "?
Rashi #1: To incorporate in the denial all the prophesies that all the Nevi'im are destined to prophesy.
Rashi #2 (in Bo Sh'mos, 12:2): "min ha'Yom" teaches us that Hashem always spoke to Moshe in the daytime.
Rashbam: It refers to "Anochi" and "Lo Yih'yeh l'cha", which preceded all the other Mitzvos.
Oznayim la'Torah: It refers to all the Mitzvos of the Torah- since the people thought that they were no longer obligated to observe them. 1
Which explains the connection with The Parshah of Tz'lofchad who gathered wood on Shabbos, in order to prove via his death-sentence that the Torah was still fully intact and that the people were still obligated to observe it. See Oznayim la'Torah, who elaborates.
What are the connotations of the phrase "Min ha'Yom asher Tzivah Hashem ... le'Doroseichem"?
Kidushin, 29a: We learn from here that, wherever the Torah uses the word "Tzav" it is a Ziruz (an encouragement) that applies (immediately 1 and) for all generations. 2
Tosefta Bechoros, 3:5: It teaches us that whoever is suspect on Avodah Zarah is automatically suspect on the entire Torah - but only from now on, not retroactively. 3
