Why were there some who hoarded the manna?
What turned Wormy before it even spoiled?
Why did Yisro arrive right after the disaster at Rephidim?
Moshe said to them, “let no man leave any [mann-manna;] over until morning.â€But they did not listen to Moshe, some men left some over until morning and it became maggoty with worms and putrid and Moshe grew angry at them.
— Shemos 16:19,20
And putrid: This verse is transposed, because it first became putrid and only later did it grow maggoty with worms, as it says: “It did not putrefy nor become maggoty with worms.†(ibid:24), and such is the natural progression of all things that become wormy.
— Rashi ibid citing Mechilta
They put it [the extra portion of mann that fell on Friday] away until [Shabbos] morning as Moshe had commanded. It did not putrefy nor become maggoty with worms.
— Shemos 16:24
The entire community of the Bnei Yisrael-the children of Israel; moved on from the Sin Desert traveling by the word of G-d, until they camped in Rephidim.
— Shemos 17:1
Moshe named the place [Rephidim] Testing-and-Argument after the quarrel of the Bnei Yisrael and after their testing of HaShem. They had asked “Is HaShem within us or not?â€
— Shemos 17:7
To every thing there is a phase, and a time to every purpose under the heaven …   A time to love, and a time to hate; a time for war, and a time for peace.Â
— Mishlei 3:1,8
The lashon kodesh-Torah Hebrew; homograph/homophone middah can be defined as both a psycho-spiritual tendency, as in middos tovos-refined character traits, or as a unit of/ a tool for calculating measurements, as in middos umishkalos-measures and weights. From Maimonides to Rav Eliyahu Lazer Dessler (see Michtav m’Eliyahu II pp. 248-249), many baalei mussar-Jewish ethicists; explain the common root of these two dictionary entries as deriving from the truth that all of our psycho-spiritual tendencies are meant to be weighed, measured and applied in a precise, deliberate manner, at the proper time and under the correct conditions. Millimeters and kilometers are both true and valid metric units. But woe to the one who measures his footraces in millimeters and who gauges the thickness of his glass lenses in kilometers.
Even those middos that we consider to be intrinsically good can turn negative if pursued or applied excessively — nothing fails like excess. The obverse of this coin is that there are no intrinsically evil middos and that we are meant to play the entire hand that G-d has dealt us. Perhaps the milk of human cruelty, jealousy and stinginess needs to be doled out with an eye-dropper and at very infrequent intervals (or even once in a lifetime) but as long as the eye dropper is wielded with measured, precisely calibrated applications, then cruelty, jealousy and stinginess become good middos as well.
Moreover, just as a merchant can put his thumb on the scale or otherwise falsify his weights and measures to short-change the customers, there exist counterfeit, false middos shebenefesh– psycho-spiritual tendencies; that somewhat approximate, but that misrepresent and counterfeit, the genuine article. The Izhbitzer examines two middos at the root of two narratives in our sidrah-weekly Torah reading; in light of this.
What motivated those who defied Moshe and left over a portion of their mann for the following day? Most would aver that they lacked faith and trust in G-d, that despite already experiencing the mann’s miraculous descent from heaven and its extraordinary capacity to sustain them, they somehow felt that HaShem would not deliver on His promise the following day. But this really beggars credulity. Why would anyone believe that HaShem would cause the mann to fall one day and fail to do so the next day?
The Izhbitzer maintains that their hoarding derived from not believing in themselves, from a self-confidence deficiency. In modern terms we’d call this low self-esteem or an inferiority complex. He says that the hoarders did not doubt HaShem’s munificence to the entirety of k’lal Yisrael-the Jewish people; and were sure that the following day mann would fall from heaven for k’lal Yisrael … just not for them personally — that somehow their particular allotted portions would be missing. The Izhbitzer sharply condemns their low self-esteem terming this ersatz, counterfeit humility anavah beushah– rancid, putrefied humility. Then as now, some people of a particular religious sensibility mistake low self-esteem for anavah-humility; a most laudable middah.   But the Izhbitzer teaches that no individual should consider themselves worse or less deserving than the balance of k’lal Yisrael. This is either taking humility to an exaggerated, and thus counterproductive, extreme or it is coming from an unhealthy element in the person’s makeup and is not sourced in true humility at all.
Some might view his position about extreme anavah to be novel inasmuch as Maimonides , who advocated the golden mean between extremes for other middos , rules (Hilchos Deos 2:3) that when it comes to the polar opposites of gaavah-arrogance; and shiflus-lowliness; one should not settle for moderate anavah, but should pursue extreme anavah to the point of shiflus.
I might add that per the Izhbitzer, the passuk-verse; that says that things became wormy before spoiling and becoming putrid may not be a transposition at all. One of the most famous similes in TeNaCâ€h for anavah is when Dovid the King declared “I am a worm and not a man ; a reproach of men, and despised of the people.†(Tehillim 22:7). Perhaps the phrase “and it/ he became maggoty with worms†refers to the self-image of the hoarders, they viewed themselves as maggots — despised of and inferior to, all the other people. This “becoming maggoty†is what goaded them to save a portion of their mann for tomorrow, it was only after their own self-image became wormy that the mann spoiled and putrefied.
A straightforward reading of the episode of Rephidim yields an understanding of a sin of being, once again, a deficiency of faith in G-d and /or ingratitude. But the Izhbitzer sees it as a poorly timed desire for prominence and self-actualization. He calls it hisnaasus-being “uplifted†prominent or salient. It was poorly timed because just as a lamplight is of no use at high noon (Chulin60B) so too the light and luminescence of individual Jews were superfluous while basking in the radiant light of Moshe Rabbeinu’s sun.
This was “the quarrel … and test of G-d asking ‘Is HaShem within us or not?’â€Â When HaShem is within a person then they should be able to achieve self-actualization, salience and generating light and warmth in their own unique and inimitable way. In this case it seems that the middah of healthy self-esteem was proportionate. The lack of balance and measured-ness that corrupted the middah was that it was premature. The healthy outlet for and application of hisnaasus awaited the arrival of Yisro-Jethro. By setting up a judicial hierarchy Yisro created a system in which the lesser lights of individual Jews could shine forth, with everyone knowing their place of prominence, despite the sun of Moshe Rabbeinu.
So whether it is too much fanatical humility or premature, impetuous self-confidence and self-actualization, anavah beushah or hisnaasus, we may draw lessons of the crucial make-or-break significance of precise calibrations and measures when speaking of middos as character traits.
~adapted from Mei Hashiloach Beshalach  Dâ€H  v’Lo and Dâ€H  Vayavo
Rashi brings a Midrash that Dasan and Aviram were those who left over from the mann but
A. That is the daled of pardes not the pey.
B. While I did not research it I’d wager a safe bet that there exist Midrashos chalukos on this point.
C.Perhaps as the Ohr HaChaim states explicitly in a number of places throughout his commentary, the Izhbitzer does not shy away from arguing on a Chazal when it does not impact halachah l’maaseh.
Dathan and Aviram were guilty of many sins, hence I don’t understand why the Izhbitzer attributes their thought process to humility. Rightly so, they were not deserving!