US-P18.099ab ।US-P18.099cd ॥
In plain words
Once the meaning of the teaching is fully grasped through scriptural and ordinary usage, the Veda declares 'You are That' simply to dispel the listener's delusion.
Close to the Sanskrit
Thus, when the meaning of the sentence is known through the established validity of scripture and world, scripture declares 'That you are' for the removal of the listener's delusion.