what Spirit witnessing?
it doesn't say that!
it says if you are speaking in a language no one else knows, you're edified because YOU know what the message is...in your spirit.
God gave it to you.
so when you speak it, you are edified, CUZ YOU DIG IT.
nobody else does unless they speak the lingo or there's a translator.
LOOK:
chinese man teaching in chinese.
he is happy, edified, because he knows what he said and wrote.
but....his pupils don't understand chinese.
are they edified?
NO.
so should that teacher keep teaching them?
HOW would that edify them?
or should he BE QUIET and be edified himself by speaking to God in chinese because he and GOD know what he is saying.