In the process of 'Qiyas' (analogical deduction), which component refers to the original case that already has a ruling established by the Quran or Sunnah?

Explanation

In Qiyas, 'Asl' refers to the original case, event, or issue for which a ruling ('Hukm') already exists in the primary sources (Quran or Sunnah), and which shares an 'Illah' (effective cause) with the 'Far'' (new case).