فَإِنَّ الْخَبَرَ كَلَامٌ يَكُونُ لِنِسْبَتِهِ خَارِجٌ
A report expresses a relation whose correspondence or noncorrespondence can be judged against what is the case.
In “The water is cold,” water is the subject and coldness is what is predicated. “The water is not cold” denies that predication. Each statement is evaluated by the water's condition, not merely by the words employed.
The external counterpart of a relation does not mean that an additional physical object called a “relation” must be sitting in the room. It means that the affirmation or negation is assessable in light of reality independently of the assertion itself.