Parmenides, expressibility and pure being

In my previous post I translated Parmenides fragment 8. Among the most perplexing frustrations, and trust me, there are many in an ancient epic hexameter poem, was the phrase I translated as, “Thought and that thing on account of which thought exists are both the same thing. For not without being, within which thought has been expressed, will you discover thinking.

I had previously struggled to understand what the sentiment was which Parmenides was conveying.  On reflection, and perhaps with an appreciation for the midnight startle I woke up with pondering this sentence over and over again, and moreover, with the over-familiarity I have gained in having translated this sentence “into being”, I now think it rather a straightforward, but not obvious argument.

If there were no existence, nothing existing at all, we would not be able to express anything, for that very expression of something would itself be existing, (because it is something) and then something would, in fact, exist.  The fact that something is verbally expressed demonstrates that something exists, namely at least the expressed and the expresser.  In this sense they are the same thing.

Does Descartes simply steal a version of this argument away from Parmenides, or adapt it?  “I think, therefore I am”, is closely akin to “I speak, therefore I am”, or perhaps more basically, “It is expressed, therefore it exists.”

Any Cartesians out there have a thought (and who also exist)?