This is a translation of the famous classical work "Iqtidaa-ul-'Ilm al-'Amal" (Knowledge Mandates Action) of Al-Khateeb Al-Baghdaadee (Died 463H). It is the second installment in the classical Knowledge series - acollection of selected scholarly works from the past that deal with the subject of religious knowledge. In this treatise, the author gathers over 200 narrations from the Prophet, his Companions and the pious predecessors on the virtue and obligation of acting upon knowledge. Thus the work serves as an inspiration and encouragement to the readers, guiding them to transfer whatever knowledge they gain of Islaam into good deeds and righteous actions. You will find this book filled with beautiful admonitions and golden words of advice from our righteous predecessors, inciting us to acquire knowledge and to then put it into practice by way of acts of worship.