Qiyaas is a Daleel Shar’iy for the Ahkaam Ash-Shar’iyah and this has been established (or proven) through Qat’iy (definite) Adillah (evidences) and (supported by) Adillah Zhanniyah (indefinite evidences).

The Qiyaas that is considered is the Qiyaas in which its ‘Illah (reasoning) has been guided to by the Shar’a from the Qur’aan or the Sunnah or the Ijmaa’ As-Sahaabah. As such considering Qiyaas as a Daleel Shar’iy is an inevitable matter because Qiyaas in its true reality represents the extraction or deduction (Istinbaat) of a Hukm Shar’iy from these three Adillah (evidences). Therefore, the Daleel (evidence) of Qiyaas is the same as the Daleel of the Nass (text) that has indicated or guided to the ‘Illah.

As such, if the Daleel of the ‘Illah is the Qur’aan Al-Kareem then the Daleel of the Qiyaas is the Daleel of the Qur’aan. This is like His Qawl Ta’Aalaa in Soorat ul-Jumu’ah:

That is because this Aayah indicates the prohibition (Tahreem) of conducting trade at the time of Salaat ul-Jumu’ah due to the distraction from performing the Salaah. If we were then to say that leasing or hiring (Ijaarah) at the time of Salaat ul-Jumu’ah is Haraam in analogy to the trade, then we would have deduced the ruling of prohibition of Ijaarah at the time of the Jumu’ah prayer from the Aayah by way of Qiyaas (analogy). Consequently, the Daleel of Qiyaas in this case is the Daleel mentioned in this Aaayah of the Qur’aan Al-Kareem.