Qiyas is not a bid'ah since it does not satisfy the conditions of a bid'ah.
Sources of legislation in Islam
Sources of Islamic legislation are the Qur'an and the Sunnah of the Prophet (ﷺ). Al-Shafi'i said in his book "Jimaa' Al-'Ilm" (جماع العلم):
ولا يلزم قول بكل حال إلا بكتاب الله أو سنة رسوله (ﷺ) وما سواهما تبع
لهما
No point of view is binding unless it is based on Allah’s book
[Qur'an] or His Messenger's Sunnah, and any other points of view [not
explicitly in either] must follow [or be based on] them.
NOTE: My own translation, so treat with care.
Qiyas
As there are matters that emerge constantly, and the direct revelation from Allah stopped with the death of the Prophet (ﷺ), scholars look at consensus (ijmaa') and analogy (qiyas), among other means, to deduce a legislation.
Qiyas is defined by Ibn Qudamah in his book Rawdat Al-Nadhir wa Jannat Al-Manadhir (روضة الناظر وجنة المناظر), Vol. 2, p. 141 as:
حمل فرع على أصل في حكم بجامع بينهما
Giving a ruling concerning an unprecedented matter [not explicitly
mentioned in legislation sources] by analogy of a branch [taxonomy
child] to a stem [taxonomy parent] on the basis of some common
attributes.
NOTE: My own translation, so treat with care.
The Prophet (ﷺ) taught us the principles of qiyas. In Sahih Muslim 13/199, and Sahih Al-Bukhari 96/46, the Prophet (ﷺ) demonstrated the principles and application of qiyas on matters related to pilgrimage and fasting. There are several other examples that were the basis that all four jurisprudence (fiqh) schools adopted qiyas as the fourth source of rulings after Qur'an, Sunnah, and consensus (ijmaa').
Bid'ah
Linguistically, bid'ah means initiation without precedence. Islamically, bid'ah is defined by Ibn Taymiyyah in his book "The Great Compilation of Fatwa" 26/172:
والترك الراتب سنة كما أن الفعل الراتب سنة، بخلاف ما كان تركه لعدم مقتض
أو فوات شرط أو وجود مانع وحدث بعده من المقتضيات والشروط وزوال المانع
ما دلت الشريعة على فعله حينئذ
Ibn Taymiyyah says that Sunnah applies to both adopting as well as not adopting a practice, then defines bid'ah as the opposite of Sunnah, while having the following elements:
- A religious act (deed or words) with the intention of getting closer to Allah
- It was not practiced nor approved nor condoned by the Prophet (ﷺ), while during the life of the Prophet (ﷺ), there was a need for such act under similar conditions at the time of doing qiyas, and there was no inhibitor that stopped the Prophet (ﷺ) from performing said act.
Ibn Qayyim al-Jawziyya had a very similar definition in his book "Information for Those who Write on Behalf of the Lord of the Worlds" 2/390 (إعلام الموقعين عن رب العالمين), as well as several other scholars.
Example: The Prophet (ﷺ) did not use taxis. Are taxis bid'ah? No, because using taxis is not a religious act.
Example: The Prophet (ﷺ) did not listen to Qur'an on MP3 players. Is this is a bid'ah? No, because while the need to listen to Qur'an was there at the time, there was an inhibitor (MP3 players were not yet invented).
Is qiyas a bid'ah?
Applying the conditions of bid'ah:
- Is qiyas a religious act? Yes.
- Was qiyas practiced by the Propet (ﷺ)? No, but it was demonstrated by him.
- Was there a need during the time of the Prophet (ﷺ) to practice qiyas? On a temporary basis (in between revelations), yes. On a permanent basis, in such situations, Allah revealed to the Prophet (ﷺ) afterwards what the correct practice or principle was (e.g., the torture in the grave was initially believed to be for non-Muslims only, but Allah revealed to the Prophet that it applies to all as per Sahih Muslim 5/157).
- Was there a condition to practice qiyas that was not satisfied at the time of the Prophet (ﷺ) that is satisfied now? Potentially yes, with matters that emerge that were not present at the time.
- Was there an inhibitor for the Prophet (ﷺ) to use qiyas? Yes, he used to get direct revelations from Allah.
Since not all conditions of a bid'ah are satisfied, qiyas is not a bid'ah.