What I'm going to write about is rather obvious, I reckon, but I had my fun investigating this.
Today, I came across the Nedroid Comics post quoting familiar verse about an omniscient mirror: "Mirror, mirror on the wall, who is the fairest of them all?"
I rushed to search engines to discover that this phrase belongs to Snow White famous cartoon. Then, I became curious about its connection with the fairy-tale by Pushkin. That's why I had started apologising - I had never realised that those two stories are almost similar before. Dwarfs or knights, not a big difference, but had I never have such an idea until today. Shame on me.
So, both those stories are based on Brothers Grimm tale. Still, in that particular case, Disney's cartoon is quoted most probably - English translations of Grimm's tale that I had managed to find, are of another meter and use "looking glass" term instead of "mirror":
"Looking-glass, Looking-glass, on the wall, who in this land is the fairest of all?"
Bonus: Brutal heavy metal fans doing their own research on the rhyme. Maybe I don't have to be so ashamed.