I have a question regarding this quote circulating on the internet of Imam Ali purportedly saying this quote:

"Asceticism is not that you should not own anything, but that it should not own you."

Is there a source for this quote? And is it 'sahih'?

How does one properly attain 'zuhd' from wordly desires and how can one achieve that 'middle road' of enjoyment of life and ibadat of Allah (swt).

I am not sure of this hadith as i have not seen it.

As for achieving the middle road one should not be extreme in either direction. One should balance their things in life.