US-P19.018ab ।US-P19.018cd ॥
In plain words
Because everything dual is a mental fabrication possessing alien attributes—as scripture and tradition have long established—it is systematically negated here through the 'not this, not this' inquiry, leaving only the ultimate truth behind.
Close to the Sanskrit
And from mental construction also, possessing different attributes, from śruti, from prior establishment also, duality is imagined; and 'not this, not this', thus whatever is imagined is negated here also for the establishment of the remainder.