Sufi theoreticians on the one hand cut their definitions of annihilation of self and Oneness with God exceedingly fine, while ecstatics on the other, the "drunken Sufis" who did not share Junayd's measured sobriety, followed whither their fevered experience and expressions led them. The result was, not unpredictably, a conservative reaction, or at least a degree of caution, and in the first instance on the part of certain Sufi masters themselves. One such was al-Sarraj (d. 988 C.E.), whose great systematic treatise on Sufism ends with a kind of syllabus of errors directed at Sufi theory and practice.

Some mystics of Baghdad have erred in their doctrine that, when they pass away from their qualities, they enter into the qualities of God. This involves infusion (hulul) or leads to the Christian belief concerning Jesus. The doctrine in question has been attributed to some of the earlier (Muslim) mystics, but its true understanding is this: when a man goes forth from his own qualities and enters into the qualities of God, he goes forth from his own will, which is a gift to him from God, and enters into the Will of God, knowing that his will has been given to him by God, and that by virtue of this gift he can stop regarding himself and become entirely devoted to God. This is one of the stages of those who seek after Oneness. Those who have erred in this teaching are the ones who have failed to note that the qualities of God are not the same as God. To make God identical with His qualities is to be guilty of infidelity, because God does not descend into the heart but what does descend into the heart is faith in God and belief in His Oneness and reverence for the thought of him. (Sarraj, The Splendor of Sufism 432) [Cited in JUNAYD 1962: 84]

Some have abstained from food and drink because they fancy that, when a man's body is weakened, it is possible that he may lose his humanity and be invested with the attributes of divinity. The ignorant persons who hold this doctrine cannot distinguish between humanity and the innate qualities of humanity. Humanity does not depart from a man any more than blackness departs from that which is black or whiteness from that which is white, but the innate qualities of humanity are changed and transmuted by the all-powerful radiance that is shed upon them from the Divine Realities. The attributes of humanity are not the essence of humanity. Those who speak of the doctrine of obliteration mean the cessation of our regarding our own actions and works of devotion through continuously regarding God as the doer of those acts on behalf of His servants. (Sarraj, The Splendor of Sufism 426) [Cited in JUNAYD 1962: 84–85]