Qiyas is an Islamic legal term that refers to the process of analogical reasoning used to derive legal rulings. It involves comparing a new situation or issue to a known case in Islamic law, allowing scholars to apply established principles to contemporary matters. This method helps maintain consistency and relevance in Sharia law. In Qiyas, the original case is called the "asl," while the new case is referred to as the "far." Scholars analyze the underlying reasons or causes (known as "illah") behind the original ruling to ensure that the same reasoning applies to the new situation, thus facilitating the evolution of Islamic jurisprudence.