Page 260 ... "In a nutshell, oneness of Being (Wahdat-al-Wujud) in Islam means that nothing in this world can contain God, but God contains everything. Or nothing is God, but nothing is separate from God. That is why the concept of hulul and ittihad (incarnation) are against the tenets of Islam. Hulul and ittihad presuppose multiplicity of being, whereas Islam proclaims oneness of Being ... that is Divine Being. This concept of God does not violate the principles of Shari'ah in any way. What happens in the state of fana-fi-Allah is that man does not become God, but he is lost in God's Being. Like an iceberg which when frozen, assumes a separate existence, and becomes one with the sea when it melts. Similarly, when the seeker is in the state of fana, he is one with God and when in baqa, he assumes the shape of an iceberg, cold, hard, and limited."
Page266 ... "Again Shibli says, 'tauhid veils the Unitarian from seeing the beauty of His oneness.' This is because tauhid is the act of man, and the act of man cannot be the means (illat) of seeing God and what cannot be the means of seeing God, is necessarily a veil. Man, with all his attributes is something other than God because if his attributes (sifat) are regarded as Divine Attributes, then man who is the possessor of these attributes becomes Divine, and then the Unitarian (muwahhid), Unity (tauhid) and the One (wahid) become intedependent. And this is precisely the Christian notion of Trinity. The attribute which veils a man from reaching tauhid (oneness) is a veil. And one who is veiled is not a Unitarian (muwahhid), for other than God in the universe is non-existent."