US-P17.031ab ।US-P17.031cd ॥
In plain words
That Self is to be known directly, and only directly. Śruti says it in so many words: the Self, directly. And it says the knot in the heart is split open — which it would not be, if the knowing were anything less than direct.
Close to the Sanskrit
Directly indeed is He to be known, because of the śruti 'directly, the Self'; and because of the śruti beginning 'the knot of the heart is split' — for if not [directly], it is not split.