Five Types of Knowledge (Which Constitute)
Life, Nourishment, Medicine,
Disease and Destruction
Yahyaa bin Ammaar (d. 422H) said:
العلوم خمسة علم هو حياة الدين وهو علم التوحيد وعلم هو قوت الدين وهو العظة والذكر وعلم هو دواء الدين وهو الفقه وعلم هو داء الدين وهو أخبار ما وقع بين السلف وعلم هو هلاك الدين وهو الكلام
Types of knowledge are five: Knowledge which is the life of the religion, that is the knowledge of Tawhid. And knowledge which is the nourishment of the religion, that is admonition and remembrance. And knowledge which is the (medicinal) treatment of the religion and that is fiqh (knowledge of rulings with their proofs). And knowledge which is the disease of the religion, and that is (the) reports about what occurred between the Salaf (the Companions). And a knowledge which is the destruction of the religion and that is kalaam.
Al-Siyar of al-Dhahabi (17/482).
Source:http://www.salaf.com & http://maktabasalafiya.blogspot.com/