वपुरिन्द्रियादिविषये याहंबुद्धिर्महत्यसौ भ्रान्तिः ।तद्बुद्धिरतस्मिन्नित्यध्यासत्वेन शास्यमानत्वात् ॥ ८६ ॥
In plain words
The sense of 'I' that lands on the body, the senses, and everything of that order — that is the great delusion. This is exactly what the teaching calls adhyāsa: holding the notion of that in what is not that.
Close to the Sanskrit
Whatever 'I'-notion there is in the sphere of the body, the senses, and the rest — that is a great delusion, because it is taught, as superimposition, to be 'the notion of that in what is not that'.