Almost! With context: "One of the surest of tests is the way in which a poet borrows. Immature poets imitate; mature poets steal; bad poets deface what they take, and good poets make it into something better, or at least something different."
I'm also a fan of the way Gilles Deleuze framed it: "Proust says: 'Great literature is written in a sort of foreign language. To each sentence we attach a meaning, or at any rate a mental image, which is often a mistranslation. But in great literature all our mistranslations result in beauty.' This is the good way to read: all mistranslations are good -- always provided that they do not consist in interpretations, but relate to the use of the book, that they multiply its use, that they create yet another language inside its language. 'Great literature is written in a sort of foreign language...' That is the definition of style."
I don't see the connection to Deleuze. Eliot isn't talking about mistranslation or about how audiences receive art. He's talking about Dylan lifting the melody to "Don't think twice" from some other song.
Of course how audiences receive art and how artists create it aren't disjoint processes, but I understand you getting hung up on Deleuze's use of the word "mistranslation" there. It helps to know that he's working out of a tradition that treats the idea of translating as a figure for "owning" (in the Heideggerian sense, also translated "enowning").
It doesn't help to replace one obscure jargon with another, even more obscure jargon.
I believe it's Emerson. But Steve Jobs might well have adopted it, like the fake Leonardo quote ("simplicity is the ultimate sophistication" - actually William Gaddis) and the fake Picasso one ("great artists steal" - actually T.S. Eliot).