The following quotations of the scholars of Shariah regarding the precedence of the knowledge and science of Tasawwuf, (Purification of the Self)
Imam Abu Hanifa (85 H. – 150 H) “If it were not for two years, I would have perished.” He said, “for two years I accompanied Sayyidina Ja’far as-Sadiq and I acquired the spiritual knowledge that made me a gnostic in the Way.” [Ad-Durr al-Mukhtar, vol 1. p. 43]
Imam Malik (95 H. – 179 H.) “whoever studies Jurisprudence (tafaqaha) and didn’t study Sufism [tasawwafa] will be corrupted; and whoever studied Sufism and didn’t study Jurisprudence will become a heretic; and whoever combined both will be reach the Truth.” [the scholar’Ali al-Adawi , vol. 2, p 195.)
Imam Shafi’i (150 – 205 AH.) “I accompanied the Sufi people and I received from them three knowledges: … how to speak; .. how to treat people withleniency and a soft heart… and they… guided me in the ways of Sufism.” [Kashf al-Khafa, ‘Ajluni, vol. 1, p 341.]
Imam Ahmad bin Hanbal (164 – 241 AH.) “O my son, you have to sit with the People of Sufism, because they are like a fountain of knowledge and they keep the Remembrance of Allah in their hearts. they are the ascetics and they have the most spiritual power.” [Tanwir al-Qulub p. 405]
Imam Ghazzali (450 – 505 AH.) “I knew verily that Sufis are the seekers in Allah’s Way, and their conduct is the best conduct, and their way is the best way, and their manners are the most sanctified. They have cleaned their hearts from other than Allah and they have made them as pathways for rivers to run receiving knowledge of the Divine Presence.” [al-Munqidh, p. 131].
Fakhr ad-Din ar-Razi (544 – 606 AH) “the way of Sufis for seeking Knowledge, is to disconnect themselves from this worldly life, and they keep themselves constantly busy …. with Dhikrullah, in all their actions and behaviors. [‘Itiqadaat Furaq al-Muslimeen, p. 72, 73]
Imam Nawawi (620 – 676 AH.) “The specifications of the Way of the Sufis are … to keep the Presence of Allah in your heart in public and in private; to follow the Sunnah of the Prophet (s) … to be happy with what Allah gave you…”[in his Letters, (Maqasid at-tawhid), p. 201]
Ibn Khaldun (733 – 808 AH.) “The way of the Sufis is the way of the Salaf, the preceding Scholars between the Sahaba and Tabi’een of those who followed good guidance…” [Muqaddimat ibn al-Khaldun, p. 328]
Tajuddin as-Subki (727 – 771 AH.) “May Allah praise them [the Sufis] and greet them and may Allah cause us to be with them in Paradise. Too many things havebeen said about them and too many ignorant people have said things which are not related to them. And the truth is that those people left the world and were busy with worship. … They are the People of Allah, whose supplications and player Allah accepts and by means of whom Allah supports human beings” [Mu’eed an-Na’am p. 190, the chapter entitled Tasawwufl
Jalaluddin as-Suyuti (849 – 911 AH.) “At-Tasawwuf in itself is the best and most honorable knowledge. It explains how to follow the Sunnah of the Prophet (s) and to put aside innovation.” [Ta’yid al-Haqiqat al-‘Aiiyya,p 57]
Ibn Taymiyya (661 – 728 AH) “Tasawwuf has realities and states of experience which they talk about in their science. Some of it is that the Sufi is that one who purifies himself from anything which distracts him from the remembrance of Allah and who will be so filled up with knowledge of the heart and knowledge of the mind to the point that the value of gold and stones will be the same to him. [Majmu’a Fatawi Ibn Taymiyya, Vol. 1 1, p. 314].
lbn Qayyim (691 – 751 AH.) “We can witness the greatness of the People of Sufism, in the eyes of the earliest generations of Muslims by what has beenmentioned by Sufyan ath-Thawri (d. 161 AH), one of the greatest imams of the second century and one of the foremost legal scholars. He said, “If it had not been for Abu Hisham as-Sufi (d. 115) 1 would never have perceived the action of the subtlest forms of hypocrisy in the self… Among the best of people is the Sufi learned in jurisprudence.” [Manazil as-Sa’ireen.]