The linguistic meaning of the (word) daleel is the indicator (daleel), and the word daleel can be used for what has indication and guidance, and this is what is named daleel in the definition set by the jurisprudents, as they defined it by: which the correct scrutinize in it leads to an announced request (matloub khabari). As for the daleel of the usoul (principals); they defined it by: what leads to the knowledge about the announced request, in another word it is that which is taken as evidence, (to prove) that what is searched for is a shari'ahi verdict.

Every shari'ahi daleel indicates the verdict decisively or indecisively. If the daleel indicates decisively, for it is decisively transmitted like the Qur’an and the motawaatir hadeeth, and its indication is also decisive; there is no dispute over its consideration, and if it indicates the verdict indecisively, but its origin (transmission) is decisive like the Qur’an and the motawaatir hadeeth; it is also considered. If its origin is indecisive like the ahaad (individually narrated) hadeeth, then it is a must to verify it, i.e. making sure of the authenticity of the hadeeth before deciding to accept it, and it is not right to accept it unrestrictedly. If the hadeeth is veritable (sahih); it must be accepted even if it is indecisive, because the individually narrated (khabar) that has an authentic issuance is considered as an evidence, even if its issuance is indecisive, and the verification is to know the authenticity and to be tranquilled that it is issued by the prophet (SAW). The shari'ahi evidences are of two types: one of them is related to the expressions (words) of the text and what is denoted by their literal meaning (mantouq) and their connotation (mafhoum). The second type is related to the reasoned meaning (ma’qoul) of the text, i.e. related to the shari'ahi illah (reason of the legislation). As for the first type of the evidences: that is the book (of Allah Ta’ala), the Sunnah and the Ijmaa’ of the Sahaabah (consensus of the Sahaabah). The second type is the (Qyas) scholarly measuring (analogy), which needs the shari'ahi illah that is showed in the shar,i text.

The evidence is not considered to be shari'ahi unless it came from The Messenger (SAW) either through the text or what the text denotes, which is related to the text, otherwise it is not considered to be shari'ahi daleel. As for the text, it is certainly a daleel, whether it is recited which was revealed as text and meaning, and that is the Qur’an, or not recited, which was revealed as meaning, and The Messenger (SAW) expressed it by His words, action and approval, and that is the Sunnah. As for what the text denoted, that is considered to be a daleel if its denotation is related to the text itself (not to the ijtihaad), and that is the Ijmaa’ of the Sahaabah, and the Qyas. As for the Ijmaa’ of the Sahaabah, it is considered to be shari'ahi daleel because it discloses that there is a daleel of the text (the Sunnah), and its disclosure makes the evidence for it related to the text itself, and also the texts which came from The Messenger (SAW) denoted the consideration of their Ijmaa’ as a daleel. That is because there came in the Qur’an and in the Hadeeth what explicitly praised the Sahaabah and considered imitating them, and because they saw the Messenger (SAW) in the state of His speech, deed and silence (approval). So their consensus on a matter denotes that they had seen a daleel (for that matter), and it became famous to them, so they had an Ijmaa’ on the shari'ahi verdict without narrating the daleel of it. Upon that the Ijmaa’ of the Sahaabah Is considered to be shari'ahi evidence and a proof which can be based on, with regard to the denotation of the shari'ahi text on it, and with regard to that, it discloses that there is an evidence, so the evidence for the Ijmaa’ is related to the text itself. As for the Qyas; its evidence is related to the text itself, because the texts are either containing ilal (reasons of the legislation) or not containing ilal. If the text contains illah, then the illah is considered to be a proof where ever it exists, and the Qyas will be based on it, and this is the shari'ahi Qyas. If the text does not contain illah, then there is no Qyas (analogy). Also the texts which came from the Messenger (SAW) denoted the consideration of the Qyas as shari'ahi evidence; the Messenger (SAW) had guided to the Qyas and approved it. Accordingly the Qyas is considered to be a shari'ahi daleel and a proof on which verdicts can be based, with regard to the shari'ahi illah contained in the text. So the evidence on the Qyas is related to the text itself, because the shari'ahi text denoted it.