The Maharil Diskin in his commentary to the parsha raises a similar question. The Rishonim tell us that there is an issur of bal tosif in creating a new mitzvah and adding it to the Torah. What if the Sanhedrin really thinks that there is such a mitzvah – are they inadvertently violating bal tosif if they think they are obeying the Torah, not changing it?
The Shem m’Shmuel answers that true, ex post facto you can justify following the false prophet by claiming you believe he was speaking in G-d’s name. But how did you ever arrive at that belief to begin with? Someone who truly loves G-d will never become so twisted in his thinking as to not only do wrong, but think that he is obeying G-d’s prophecy in doing so.
Sadly we see many people who think they are listening to G-d by following this -ism or that -ism and their many false prophets.
2. Why in the middle of this parsha of the navi sheker does the Torah stick in a reminder that “acharei Hashem Elokeichen teilechu v’oso tira’u…” etc. Doesn’t all that go without saying?
The person who falls prey to the navi sheker is someone looking for spirituality, someone filled with idealism who wants to hear the voice of G-d. The answer to the lure of the navi sheker is not shutting down that craving for idealism and/or spirituality – the answer is redirecting it in a positive way. Whatever you seek from the navi sheker can already be found in Torah (see Seforno).
I was thinking that perhaps the key words in that pasuk are “bo tidbakun,” from which Chazal learn the principle that one imitate G-d and do chessed, visit the sick, bury the dead. The false prophet tells a person that worship consists of all kinds of ritualistic rites and ceremonies . The Torah, by contrast, emphasizes that true religion emphasizes interpersonal relationships and helping one’s fellow man. The prophet who talks only about sacrificing to some idol is clearly on the wrong track.
3. The Torah writes that eating ma’aser sheni in Yerushalayim brings a person to yiras shamayim. Tos (Baba Basra 21) explains that when a person sees the kohanim engaged in avodas Hashem he is inspired in his learning and avodah. R’ Shteinman in his Ayeles haShachar asks why this point is emphasized particularly in connection with ma’aser sheni – the Torah does not say the same thing about the mitzvah of aliya laregel that brings a person to Yerushalayim 3x a year.
I think the answer is that when you make aliya la’regel, everyone is doing it. It becomes an event. It’s true that a person would see miracles and the wonder of avodah in the mikdash during those times, but it would be in the context of the crowd and the masses all doing and seeing the same thing. When a person brought ma’aser sheni, it was a personal journey. It therefore afforded more of an opportunity for introspection, more or an opportunity to ask, “Why am I doing this and what does it mean for me?”
4. Just to leave off with something about Eretz Yisrael: the Torah writes (12:28) “shmor v’shamata es kol hadevarim ha’eileh…” commading us to keep ALL the Torah and mitzvos. The very next pasuk continues, “ki yachris Hashem Elokecha es hagoyim… v’yarashta osam v’yashavta b’artzam,” commanding us to conquer and settle Eretz Yisrael. The GR”A in Aderes Eliyahu explains the juxtoposition, the smichus haparshiyos: Eretz Yisrael is equal to all the other mitzvos combined.
Keep up the tefilos for its safety.