The rulings of the Shari'ah are based on preponderant probability, and it is not necessary for them to be definitive in their indication.

The Shaykh : That is because, in the view of the scholars, preponderant probability is sufficient for the rulings of the Shari'ah; it is not required that the probability be certainty. A judge, that is, any Muslim judge, when he issues a ruling between two parties to separate a couple, to validate a marriage, or to invalidate a marriage, is issuing a ruling based on his independent legal reasoning (ijtihad). This ijtihad is either correct or incorrect. Any ruling that is subject to doubt or hesitation between being correct and being incorrect is not called definitive; rather, it is said to be established on preponderant probability. Therefore, the jurists say that the rulings of the Shari'ah are divided into two categories in terms of the strength of their evidence: one category has definitive evidence, and the other has probabilistic evidence. Evidence is not considered definitive unless two conditions are met: that it be definitive in its establishment and definitive in its indication. If one of these two conditions is lacking, it is not definitive but rather probabilistic. It may be definitive in its establishment but probabilistic in its indication, or it may be definitive in its indication but probabilistic in its establishment. The jurists know this issue, but some of those who are aware of this distinction deceive the people by saying, for example, that there is no definitive evidence for the prohibition of musical instruments, meaning instruments of music, by which they mean definitive in establishment and definitive in indication. I warn against this misleading approach for the general Muslim public.