I continued at this stage for the space of ten years, and during these periods of solitude, there were revealed to me things innumerable and unfathomable. This much I shall say about that in order that others may be helped: I learnt with certainty that it is above all the mystics who walk on the road of God; their life is the best life, their method the soundest method, their character the purest character; indeed, were the intellect of the intellectuals and the learning of the learned and the scholarship of the scholars, who are versed in the profundities of revealed truth, brought together in the attempt to improve the life and character of the mystics, they would find no way of doing so; for to the mystics all movement and all rest, whether external or internal, brings illumination from the light of the lamp of prophetic revelation; and behind the light of prophetic revelation there is no other light on the face of the earth from which illumination may be received…
— al-Ghazali