The word sufi, usually derived from suf, supposedly in reference to the coarse woollen garments of the early Muslim mystics. Sufi poetry is centred, explicitly or implicitly, on the eternal and infinite source from which the soul of the poet originated and to which it seeks to return. One of the earliest great Sufi poems that have come down is the well-known quatrain generally ascribed to Rabiah al-Adawiyyah of Basra. Ibn Arabi is said to have been the first to write Sufi poetry in the form of the muwashshah, the lyric in stanzas with a change of rhyme and sometimes with a refrain. This chapter demonstrates the poetry of the mystics reveals certain aspects of their spirituality more clearly than any other source is capable of doing. This chapter explores Sufi poetry in the Abbasid period, where literary interests have taken precedence over other consideration.