And finally in the TNG episode "The Mind's Eye" when Picard failed to convince Governor Vagh that the Federation wasn't supplying weapons to Kriosian rebels, Vagh shouted: "You speak the lies of a *tah-keck*!" Picard calmly leaned forward and replied, "*Qu'vatlh guy'cha b'aka!*" Vagh complimented him: "You swear well, Picard. You must have Klingon blood in your veins." (Spellings from the closed captions).
Obviously the writers just strung some words together, but Vagh accepted it.