"Maybe you should stay away from these topics until you are an actual expert."
"Stick with what you know."
"Unless you have a vagina, stay away from [making decisions on] women's health."
These phrases, and others like them, are most often used by Social Justice Warriors (SJW). Frequently used when the other party has made a point with which the SJW disagrees, but cannot argue by use of logic. (That's most of the time, people.)
Of course, the underlying message - that one cannot know anything about what one has not experienced - is blatantly false. As an example - would you like to drink concrete? Of course not. Most people would agree. Yet, almost nobody has ever tasted concrete, much less drunk the stuff.
Almost all the times these phrases are used by people other than SJW fall into the category of use by a #cuckservative . Of course, a #cuckservative by definition, is a conservative who sells out. (And even Wikipedia got that one right.)
From time to time, these #cuckservatives don't even know that's what they are. Trained from an early age to use these tools, and give way when the big mean liberals attack, modern #cuckservatives can often resort to retorts like this without blinking.
The human being has the capability to understand without direct experience. To understand conceptually. Or, to put it another way: most of the feminists who blather these lines cannot understand the irony that they have a male OB-GYN. If they used their "logic" for a moment, they would never return to their doctor, as he is a man and not a woman. How could he possibly know about a woman's health?
"When the debate is lost, slander becomes the tool of the loser."
(I still say his name in my head like Bill & Ted - "Sow - crates")
On a more serious note, the phrases above, and those like them, often preclude or are intertwined with slander. The speaker / writer of the phrase knows she has lost and feels she must resort to slander.
And never forget Law 3 - SJWs always project. The SJW will often say you are slandering them in cases like this. It almost never fails!