It occurs after Pinchas's famous execution of the Shimoni prince & his Midianite floozy.
Many in Am Yisrael took offense at this because the prince held impeccable lineage from Shimon ben Yaakov while Pinchas's maternal grandfather was Yitro/Jethro—the man who once felt such devotion to the polytheistic occult that he went above & beyond in his service to idols.
His devotion to avodah zarah (idol worship) earned him the nickname "Puti"—from the word pitem ("fattened") because he fattened calves in order to offer the idols the most succulent meat.
As Rashi notes, the people disparaged Pinchas by saying:
"Have you see the son of Puti, whose mother's father fattened calves for idol worship and killed the prince of a Tribe from Israel?"
Once again, we see that it's not who you are, but what you do with yourself that matters.
Why You Need Your Disadvantages
People need to actually work in order to achieve their greatness.
They need copious prayer & siyata d'Shamya.
That's why so many our greatest Torah leaders faced innate struggles, both inside & outside themselves.
They needed those challenges to make them who they became.
It's actually harder for people born with the proverbial silver spoon in their mouth to achieve true greatness & humility.
Likewise, you find mussar in Judaism that notes how wealth tends to be a harder nisayon than poverty, although it seems the opposite.
However, Judaism notes that wealthy people need to work harder to develop empathy, humility, and generosity in line with their true financial ability to give.
My own personal experience shows that middle-to-lower-income people tend to be much more generous with their money & objects.
Rav Miller often noted that Jews in need of hospitality fared better with Jews of average means rather than the wealthy, so Rav Miller sent them to a shul where he knew these people would receive what they needed—and it wasn't from those living in lovely homes with manicured lawns.
(https://torasavigdor.org/rav-avigdor-miller-on-clean-jewish-homes/)
There are exceptions; some people understand the nisayon of wealth & rise to the occasion. But it is harder.
Many times, people with exceptional academic intelligence tend to be difficult to deal with. Not all of them, but many of them tend to be close-minded & hold irrational beliefs. (This is why so many in Western academia tend to lean so far to the Left.)
They assume that anyone who disagrees with them simply does not understand, which makes impossible any rational discussion with them.
After all, to their way of thinking, if they mastered trigonometry by 10th grade while you still struggled with algebra, how you could possibly know better than they do?
Many never realize that academic intelligence does not include emotional intelligence, practical intelligence, or a solid understanding of ethics & integrity.
(A lot—though not all!—of them also hold a really poor work ethic, always looking to earn the highest salary while doing the least amount of work, preferring to dump all their work onto subordinates. This explains why so many companies are badly run and even tank at some point. It also partially explains why so many universities fail so badly at their entire purpose of being—to educate—despite being staffed by doctorates.)
Lesser is Better!
Har Sinai was the smaller mountain.
David Hamelech was the youngest brother with a suspicious lineage (though in reality, he held the same lineage as his brothers, yet initially, no one knew that for sure).
Yitzchak Avinu & Yaakov Avinu were the younger brothers.
The highest statuses in Am Yisrael all went to younger brothers, rather than the expected firstborn: The Levi'im & Kohanim descend from Levi (son #3 of Yaakov & Leah) while the Messianic royalty descends from son #4—Yehudah.
Moshe Rabbeinu was the youngest & suffered from a speech impediment.
In the incident with the Shimoni prince and Midianite floozy, the people challenged Moshe Rabbeinu's approval of the zealous act of Pinchas, saying:
"Moshe, is this a forbidden woman or a permitted woman? If you say she is a forbidden woman, who permitted to you the daughter of Yitro?
(Rashi on Bamidbar 25:6)
The correlations they attempted to draw sound bizarre because Tzipporah joined Am Yisrael in purity & law. She married Moshe Rabbeinu in a completely kosher manner.
What is the similarity between Moshe Rabbeinu's holy marriage & the Shimoni prince's brazen pritzut?
None.
Yet we've all seen how people's minds jump to draw even the most irrational correlations to "prove" some type of hypocrisy against a person they'd like to discredit.
The Me'am Lo'ez mentions that Ruth descended from the Moavite king Balak, which means that the King of Yehudah also descended from him.
Rebbi Akiva descended from the Canaanite Sisera, the evil tormentor of Am Yisrael during the leadership of Devorah & Barak. Canaan is particularly repellent because it was a cursed nation.
This list goes on.
Real Hypocrisy—It's Not What They Think
That peddler himself was a former gossiper & tale-bearer—a rochel.
Having done teshuvah, he now sought to spread his newfound knowledge & teshuvah to others.
But rather than accepting him as he was now, the people gathered around him to put him in his place.
"Take the board from between your own eyes!" they mocked him. "Look at your own faults!"
The thing is...he DID look at his own faults! That's how he did teshuvah.
Yet the people insisted on looking "behind" the atoning peddler. They persisted in focusing on how he had been before, rather than how he was now.
Only the wise Rav Yannai saw the truth of the peddler's behavior and showed interest in the famous elixir of life.
(For the full commentary on this episode, please see: http://www.myrtlerising.com/blog/part-ii-the-happy-cure-for-blabbermouthed-fault-finders-aka-the-kli-yakar-on-parshat-metzorah)
What They Say is True...And? So What!
Moshe was married to a descendant of Midian.
Pinchas's maternal grandfather really was Yitro (though his mother descended from Yosef Hatzaddik), and Yitro really was a zealous idolator before he joined Am Yisrael.
The peddler atoning for his sins of the tongue by "peddling" the laws of guarding one's tongue really had been a terrible transgressor in this area.
It's all true!
Maybe your background really is wonky & you really did use to act like a jerk.
And the Torah comes to tell us: So what?
Even when people point it out (which is forbidden, by the way), we learn that your lineage or former sins do not matter as long as you have distanced yourself from those influences.
In other words, their seemingly savvy & sophisticated criticism ("Ah-ha! Caught you!") is actually null & void, according to Torah hashkafah.
All that matters is that you have turned from evil & now invest in being good, whether that means your background or your deeds.
The Torah informs us that it is not who you are or were, but what you have done with yourself that matters.