Moulana Harun Zangipri's work highlighted in http://www.al-islam.org/abudharr/10.htm

Excerpt from the book:
Chapter 7

There are countless exhortations which the Prophet made to Abuzar. We here throw light on a few of them. Moulana Muhammad Harun Zangipuri writes on the authority of "Amali" of Shaykh Tusi that the Prophet said to Abuzar:
“O Abuzar! Worship Allah as if you are seeing Him, or He is seeing you and even if you are not seeing him”.
Know that His foremost worship is His cognition i.e. to understand that He is the First before whom there was none. He is One without a partner. He is Eternal having no end. He is the Creator of all things between the earth and the heavens. He is Pure and Omniscient. He is Free from every blemish, and is the Creator of all things