but there are comments on a selection of verses. A Sufi commentary of the Quran is attributed to Jafar al-Sadiq (Tafsir Imam Ja'far al-Sadiq), but its authenticity remains suspect. It conveys a spurious textual tradition and has little reliable material, but the items cited on Jafar Sadiq's authority in Sulami's book appear to be based on identifiable chains of transmitters. From the 11th century, several other works appear such as commentaries by Qushayri (d. 1074), Daylami (d. 1193), Shirazi (d. 1209), and Suhrawardi (d. 1234). These works include material from Sulami's books as well as the author's own contributions. Many works are written in Persian, such as the works of Maybudi (d. 1135) kashaf al-asrar ("the unveiling of the secrets"). Rumi (d. 1273) wrote a vast amount of mystical poetry in his book Mathnawi. Rumi makes heavy use of the Quran in his poetry, a feature that is sometimes omitted in translations of his work. Rumi's manner of incorporating Quranic verses into his poetry is notable in that he does not use them as prooftexts but intertwines Quranic verses with his poetry. Simnani (d. 1336) wrote two influential works of esoteric exegesis on the Quran. He reconciled notions of God's manifestation through and in the physical world with the sentiments of Sunni Islam. Simnani was a prolific author, 154 titles are ascribed to him, of which at least 79 exist today. Comprehensive Sufi commentaries appear in the 18th century such as the work of Ismail Hakki Bursevi (d. 1725). His work ruh al-Bayan ("The Spirit of Elucidation") is a voluminous exegesis. Written in Arabic, it combines the author's own ideas with those of his predecessors (notably, Ibn Arabi and Ghazali). In Shiism Shia Islam is a branch of Islam in which one finds some of the most esoteric interpretations on the nature of the Quran. Shia interpretations of the Quran concern mainly issues of authority where the concept of Imamat is paramount. In Twelver Shia Islam, there are mainly two theological schools: the Akhbari and the Ususli. The former school interprets the Quran mainly through reliance upon traditions (hadith) ascribed to the Imams. The latter school gives more power to independent reasoning and judgment (ijtihad). Ismaili interpretation shares common ground with Sufism. The method is called kashf, an "unveiling" to the heart of the interpreter, and it is dependent upon the master, the grace of God, and the spiritual capacity