। ॥ २१७ ॥
In plain words
Whatever is experienced, by a given witness, is exactly what that witness attests to. But nobody can be called a 'witness' of something that is never experienced at all — the very idea makes no sense.
Close to the Sanskrit
Whatever thing is experienced by whatever [witness], that thing is witnessed by that [witness]. Witness-hood does not apply, for anyone, with regard to an object that is never experienced [by anything].