I want to know the answer to the following question:
Who said "The mlecchas are wedded to the creations of their own fancy."
All the background I'm provided with is that "The Mahabharata compliments them as "the all-knowing Yavanas" (sarvajnaa yavanaa) i.e. "The Yavanas, O king, are all-knowing; the Suras are particularly so.". Is that enough to answer the question?
Answer: yes