A Shi'ite Anthology

Via Negativa 

'Ali (A.S) said, "Praise belongs to God, whose laudation is not rendered by speakers, whose bounties are not counted by reckoners,  and whose rightfully due (haqq) is not discharged by those who strive. Grand aspirations perceive Him not and deep-diving perspicacities reach Him not. His attributes (sifah) possess no determined limits (hadd mahdud), no existing description (na't mawjud), no fixed time (waqt madud) and no extended term (ajal mamdud). He originates the creatures by His power,  looses the winds by His mercy, and fastens the shaking of His earth with boulders." 

The perfection of professing His Unity is sincerity (ikhlas) towards Him. And the perfection of sincerity towards Him is to negate attributes (nafy al-sifat) from Him, because of the testimony of every attribute that it is not that which possesses the attribute (al-mawsuf) and the testimony of every thing that possesses attributes that it is not the attribute." 

So whoso describes God-glory be to Him-has given Him a comrade (i.e. the description). Whoso gives Him a comrade has declared Him to be two (tathniyah). Whoso declares Him to be two has divided Him. Whoso divides Him is ignorant of Him. (Whoso is ignorant of Him points to Him). Whoso points to Him has delimited Him. Whoso delimits Him has numbered Him. Whoso says, 'In what is He ?', has enclosed Him. Whoso says, 'On what is He ?', has excluded Him (from certain things)." 

"He is a being (ka'in) not as the result of temporal origin (hadath), an existent (mawjud) not (having come) from nonexistence (adam). He is with everything, not through association (muqaranah); and He is other than everything, not through separation (muzayalah). He is active (fa'il), not in the sense of possessing movement and instruments. He was seeing when there was none of His creatures to be observed by Him. He was 'alone' (mutawahhid) when there was none with whom to be intimate and at whose loss to feel lonely." 

"He originated creation and gave to it its beginning without employing deliberation, profiting from experience, occasioning movement (harakah, i.e. in Himself), or being disrupted by the cares of the soul (hamamah nafs). He delays things to their times, [ mends their discrepancies, implants (in them) their natural dispositions, and makes these (dispositions) adhere to their objects. He has knowledge of them before their beginning, encompasses their limits (hudud) and their end (intiha') and knows their relationships (qara'in) and aspects (ahna'). 

Source:

al-islam.org

Other Links:

A Shiite Anthology: Oneness & Discrenment

A Shiite Anthology: The Vision of the Heart