Some scholars hold the view that this habit (masturbation) falls under the category of those who seek fulfillment of their sexual desires outside the framework of marriage, and as such they are deemed transgressors. Those scholars put masturbation under the list of the forbidden categories of sexual fulfillment since it constitutes transgression of boundaries. This view is held by the Shafi’ites (followers of the Shafi`i school of fiqh).
However, some other scholars believe that the transgression meant in the aforementioned verse refers to extra-marital relations and what falls under the category of zina (adultery). According to this view, masturbation does not fall under the meaning of this verse. This view is very close to the opinion held by the Hanafites (followers of the Hanafi school), who maintain that masturbation is basically forbidden, but it may be permissible under the following conditions:
1. if the person is unmarried,
2. if he or she fears that without masturbation he/she will commit Zina, and
3. if the masturbation here is, rather than fulfilling a sexual desire, just to release the sexual tension resulting from stimulation.
I conclude that the general principles of Shari`ah go against this habit, because it is not the normal way of fulfilling sexual desire; however it is a deviation -– and that is enough to condemn it, even though this act does not fall under the category of absolute prohibition like zina. However, the law of necessity, which is one of the principles of Shari’ah, should also apply here. For example, if someone is afraid that he would commit a greater sin like zina or he will be harmed by some psychological disorders, then the ban on masturbation would be relaxed just to remove the hardship, based on the Shari`ah principle that states that “necessity is judged according to the circumstances that warrant it.”