Qiyas (Analogical Reasoning)

Qiyas is the fourth source of Islamic jurisprudence after the Quran, the Sunnah, and ijma' (consensus). It is a method of analogical reasoning where a legal rule for a new situation is derived by identifying a common cause ('illah) with an already regulated situation.

In prayer legislation, qiyas is used, for example, to establish rules for situations not directly mentioned in the Quran or Sunnah. Imam Abu Hanifah was the most prominent advocate of qiyas. Imam al-Shafi'i formalized the qiyas methodology in his "al-Risalah" with strict conditions for its valid application.

Not all schools of law accept qiyas to the same degree. The Zahiri school rejected qiyas entirely, while the Hanbali school used it sparingly. Imam Ahmad ibn Hanbal said: "I do not use qiyas unless it is absolutely necessary." The discussion about the role of qiyas is fundamental to understanding why the different schools of law can reach different conclusions from the same sacred texts.