The healing ketores? The poisonous ketores?

In parshat Korach, with a plague attacking the Israelites, Moshe has an instruction for Aharon:

יא וַיֹּאמֶר מֹשֶׁה אֶל-אַהֲרֹן, קַח אֶת-הַמַּחְתָּה וְתֶן-עָלֶיהָ אֵשׁ מֵעַל הַמִּזְבֵּחַ וְשִׂים קְטֹרֶת, וְהוֹלֵךְ מְהֵרָה אֶל-הָעֵדָה, וְכַפֵּר עֲלֵיהֶם: כִּי-יָצָא הַקֶּצֶף מִלִּפְנֵי ה', הֵחֵל הַנָּגֶף.

11 And Moses said unto Aaron: 'Take thy fire-pan, and put fire therein from off the altar, and lay incense thereon, and carry it quickly unto the congregation, and make atonement for them; for there is wrath gone out from the LORD: the plague is begun.'

Ibn Ezra comments:

[יז, יא]

את המחתה -

הידועה.

ושים קטרת -

ולא אמר הקטרת והמשכיל יבין.

Thus, while the firepan is a known firepan, ketores does not get the definite article. The strong implication is that it is a different ketores from regular ketores, which has healing properties. This is a somewhat unorthodox position, and would suggest the possibility of some lack of Divine guidance in these affairs (even though it can be a miracle working via partial natural means. That Ibn Ezra says vehamskil yavin also strongly suggests that he has a somewhat edgy peshat here, and is therefore somewhat reluctant to reveal it.

Rabbi Shmuel Motot, a supercommentator on Ibn Ezra, explains:

"and place incense" -- that is to say, {incense} which is fitting for this {purpose}. And therefore it does not say haketores {with the definite article}, and the intelligent person will understand that the ketores which stopped the plague is not like the ketores which is fitting for the service {in the Mishkan}. And that which Chazal said that with that which they died, they lived, the words are there for the one who understands.

Thus, R' Motot does not only explain that this was a special incense which healed, but also that it was a special incense which killed. He is thus hinting that the ketores used by Korach and his congregation, which I would note does not have the definite article present either, was also this special incense. This is an even more radical idea. Moshe gave them poisonous ketores? On the other hand, maybe he gave the same to Aharon as well, and the herbs there could have either effect, with Hashem's influence.

See where I suggested the same idea, noting that Rabbenu Bachya actively rejects it. Also see how Avi Ezer creatively interprets this Ibn Ezra otherwise, though his suggestion is nonsensical -- that vehamaskil yavin means that the secret of ketores {meaning regular ketores} is only available to the select few, as opposed to denoting that Ibn Ezra is being cryptic and does not wish to share his perush.

Also related to this is Rashi's citation of a midrash that it was regular ketores, but that people at that time were alleging that the ketores was poisonous. One could indeed read this into the people's complaint that אַתֶּם הֲמִתֶּם, אֶת-עַם ה.

He stood between the dead…: He took hold of the angel and held him against his will. The angel said to him, “Allow me to accomplish my mission.” He [Aaron] said to him, “Moses commanded me to stop you.” He said to him, “I am the messenger of the Omnipresent, and you are the messenger of Moses.” He said to him, “Moses does not say anything on his own volition, but only at the bidding of the Almighty. If you do not believe [me], the Holy One, blessed is He, and Moses are at the entrance of the Tent of Meeting; come with me and ask.” This is the meaning of the statement, “Aaron returned to Moses” (Mid. Tanchuma Tetzaveh 15). Another interpretation: Why with incense? Because the Israelites were slandering and vilifying the incense, saying that it was a deadly poison; through it Nadab and Abihu died; through it two hundred and fifty people were burnt. The Holy One, blessed is He, said, “You shall see that it will stop the plague, and it is sin that caused their death.” - [Mid. Aggadah. See Mechilta Beshallach (Vayassa 6:5, Ber. 33a]		ויעמוד בין המתים וגו': אחז את המלאך והעמידו על כרחו. א"ל המלאך הנח לי לעשות שליחותי. א"ל משה צוני לעכב על ידך. א"ל אני שלוחו של מקום ואתה שלוחו של משה. א"ל אין משה אומר כלום מלבו אלא מפי הגבורה, אם אין אתה מאמין הרי הקב"ה ומשה אל פתח אהל מועד בא עמי ושאל. וזהו שנאמר וישב אהרן אל משה. דבר אחר למה בקטרת, לפי שהיו ישראל מליזין ומרננים אחר הקטרת לומר סם המות הוא, על ידו מתו נדב ואביהוא, על ידו נשרפו חמשים ומאתים איש, אמר הקב"ה תראו שעוצר מגפה הוא, והחטא הוא הממית:

Here, it is interesting if Ibn Ezra takes the people's complaint and declares it true.