All praise is for Allaah and may His peace and blessings be on the Final Messenger, his family and those who follow him in goodness until the Day of Judgement. To Proceed.
We are pleased to present this, our seventh E-Book, entitled: “The Book of Knowledge” - a complete translation of the classical work “Kitaab-ul-‘Ilm” of Imaam Abu Khaithama An-Nasaa’ee (rahimahullaah).
This treatise is comprised of a collection of ahaadeeth (sayings of the Prophet) and athaar (sayings of the Salaf) on the subject of Islaamic Knowledge. By reading the various narrations, it is hoped that the reader will benefit and reflect on the merits and virtues of seeking, acquiring and teaching knowledge. The treatise also provides a first-hand look on how the Salaf’s attitude was with respect to knowledge – how they sought it, how they learned it and how they taught it to others. There are several narrations, also, that give us a description of the characteristics of some of the Salaf, their knowledge and their virtues.
Therefore, this treatise is of the utmost importance, as it provides the reader with an account of the Salaf - those whom we are obligated to follow and take their example. And it deals with one of the most important topics in Islaam, which is Knowledge, since knowledge is the foundation that is required before doing all sayings and actions. Al-Haafidh Ibn 'Abd-il-Barr said:
"The scholars have unanimously agreed that there is from knowledge that which is a specified obligation upon every individual with respect to himself (fard ‘ayn) and that which is a collective obligation (fard kifaayah) – if someone rises to fulfill it, its obligation becomes withdrawn from the remaining people of that area." 
Imaam Ibn Qudaamah said:
"As for knowledge of the Religion, all of it is praiseworthy. It is divided into usool (fundamental issues), furoo' (subsidiary issues), muqaddimaat (introductory knowledge) and mutammimaat (complementary knowledge). The usool consist of the Book of Allaah, the Sunnah of the Prophet, the consensus of the Muslim scholars and the narrations of the Sahaabah. The furoo’ consist of what is understood from these fundamental sources from the meanings that are perceived by the intellect, such that what is understood from it is something other than the written wording.” 
The treatise has been verified by the great scholar of our time, Imaam Muhammad Naasir-ud-Deen Al-Albaanee. He has provided gradings for many of the narrations as well as notes and commentaries that give an explanation for some of these narrations.
We ask Allaah that He make this present E-Book a source of benefit for its readers and a source of guidance for those who act upon what is in it.
Written by: Isma'eel Alarcon
On December 16, 2001 [‘Eid-ul-Fitr]