on Don Quixote 11

on page 771, Dona Rodriguez is telling DQ about the issues that the duchess has on her legs and she says that "all that glitters is not gold". This is interesting for several reasons. One: if you wikipedia the phrase, it attributes its origin to Portia in Shakespeare's Merchant of Venice. That play was written in 1598ish almost 20 years before this second half of DQ. From what I've read, Cervantes was never even aware of Shakespeare, which makes one wonder if that is true and if maybe he stole a line, or if great minds do really think alike and they both came up with the same line independent of each other. That would be really cool if the latter was the case. Two: it is more probable that, since this is an English translation, Edith Grossman was familiar with Shakespeare's phrase and found that it would work nicely for Cervantes' similar one. Since it could maybe be translated differently it would cease to be the exact same phrase. In this case, Edith Grossman is a victim of intertextuality since she could not escape the similarities that the two works shared. Either way, I found it interesting that there was another connection, albeit a small one between the two great writers.