Is it permissible to lie to friends who only call out of need, by claiming not to possess a certain book, in order to avoid creating enmities?

Lying is forbidden by Islamic law, and it is among the ugliest of sins. However, scholars have permitted it in specific cases which are too numerous to mention here. The preferred approach when necessary is to use ma'areedh (euphemisms or double entendres). This is speech that carries two meanings, where one is intended while the other is outwardly expressed. This is permissible when there is a need for it and is not forbidden unless there is no benefit or necessity that calls for it.