There is a saying that "a small measure is not a gentleman, but a virgin is not a husband." I believe everyone is already familiar with this common saying. What does "toxic" mean here? Why do you say "no poison is not a husband"?
"Poison" refers to the measurement of human beings
As the saying goes, " prime minister can hold a boat in his belly ", which means that people who do big things are indeed very Measures. A person with a small temperament and low Measures is indeed difficult to achieve a great cause, and it is also difficult to be called a real man. As the saying goes, "A small measure is not a gentleman, and a non-toxic one is not a husband." A person with a narrow sense of dignity is not worthy of being called a gentleman, and a person without Measures is not worthy of being called a real man.

We often say "no" If "poison" is interpreted as ruthless, it cannot be read in connection with the previous sentence. A person with a low spirit is not a gentleman, and a person with a non-ruthlessness is not a real man. It is completely "a donkey's lips are not right" and it is not in line with it at all. It is also contrary to the values of ancient Chinese cultural propaganda. After checking the original text, I realized that actually does not mean "poison", but "degree". The four great masters of Yuan Dynasty Guan Hanqing in "Wang Wang" Jiangting says this:
"It's good to say: A small person is not a gentleman, and an excessive person is not a husband."
You can see that the original text is about measure, which means that a person can become a real man with measure. This common saying is combined with the first half of the sentence "a small person is not a gentleman", and the meaning is smoother: "A person with a small person is not a gentleman. Only a tolerant and generous person can become a real man."

But later, due to the level and tone, "du" and "small" are both oblique tones, which are not smooth to read, so gradually becomes "toxic".
"Poison" refers to the cruel and ruthless
It was over here, but later I checked the source of " is not a husband without poison":
yuan Wang Shifu "The West Chamber" 4th Fifth Fold: "You don't distinguish between virtuous and foolish, you are not a husband without poison."
From here we can see that "no poison is not a husband" does exist, and the source comes from the works of Wang Shifu, a Yuan musician who is as famous as Guan Hanqing. In fact, it is not difficult to find that the usage here is actually a false idiom, which refers to ruthlessness and contains a derogatory meaning. Later, more and more people used it like this, which naturally evolved into this meaning.

Conclusion : In fact, we are not accusing the mistakes of this common saying, but accusing the idiom of being used in places that should not be used. For example, some bad people say "No poison is not a husband" and then do bad things. Later, after the bad things were exposed, they still said openly that it was taught by the ancients. Of course, we must correct this wrong idea, because here it refers to a derogatory meaning.
So although this meaning exists, it does not mean that this common saying can make a sinister and cunning person correct. On the contrary, if you use this common saying alone, it will not add much glory to you.
In fact, we can understand it like this: it is true that a common saying has multiple meanings, because Chinese traditional culture has developed to this day, with praise and derogatory meanings. We cannot abandon it just because it is derogatory. On the contrary, we must use it, because this is the reason for cultural prosperity - tolerance. Therefore, no matter how many meanings it has, as long as we use it in the appropriate sentence, this common saying will not be wrong.