स्थाणौ प्रकल्पितश्चोरः स स्थाणुत्वं न बाधते ।स्वस्मिन्कल्पितजीवश्च स्वं बाधितुमशक्यते ॥ ५७ ॥
In plain words
The thief you see in the dark is only a post, and seeing him does not stop the post from being a post. In the same way, the separate person imagined in the Self cannot touch the Self, cannot cancel it, cannot make it anything other than what it is.
Close to the Sanskrit
A thief imagined upon a post — that one does not negate the post's being a post. And the jīva imagined in the Self is not able to negate the Self.