«وَآخُذُ اللَّفْظَ فِضَّةً فَإِذَا مَا صُغْتُهُ قِيلَ إِنَّهُ ذَهَبُ»
I receive words as silver; after shaping them, people call them gold.
Silver and gold are value-images for unrefined and crafted expression. The act of shaping metal becomes a metaphor for editing and composing eloquent language.
The speaker is praising his own skill, not claiming alchemy. “It is said to be gold” invokes an audience’s appreciation, which remains distinct from verification of everything the speaker asserts.