This research paper handles the issue of trading books in Islamic world by studying personal lending for Muslim scholars. The paper begins with showing the linguistic and idiomatic concept or definition of personal lending which clearly differs from lending as one of the services presented by libraries. Moreover, the study explores the extent to which Muslim scholars were interested in personal lending. It also investigates the purposes and reasons behind personal lending. Muslim scholars had different attitudes towards personal lending of books. Some allowed and encouraged personal lending but others were against to lend their books and works showing the justifications that support their views and attitudes. However, there were among those scholars who had intermediate attitude towards the issue of personal lending; they lent their books only when they had promises that ensure bringing the books back . The current paper also investigates whether there was a specific number of lent books to those who were in need of them or not. In addition, the study clarifies the extent to which borrowers of books were interested in bringing back the lent books. The paper then discusses how some borrowers misused lent books and how this made some Muslim scholars become against lending their books to those who demanded them. This case of misuse also made some other scholars put conditions and statements for personal lending to ensure the safety of their lent books and to save their rights as authors and writers . The paper concludes with collecting and showing these conditions which are scattered in various sources and references .