According to the views of the school of thought leaders and modern researchers, it is accepted that istihalah(transformation) has the ability to change the impurity (najasah) and forbidden (haram) attributes of substances. Constant changes and transformations occur in living bodies and on earth, leading to the formation of new substances. Soil, fire, air, and living organisms transform the substances they come into contact with from one state to another. Therefore, when considering a substance that has undergone istihalah, rulings should be based on its current characteristics rather than investigating its previous states.
The Qur’an provides a beautiful example of istihalah in the creation of milk, stating that milk is produced between blood and feces (Surah An-Nahl, 16:66). Clean foods consumed by the animal are transformed into blood and feces within the body, and from between these, pure milk is produced again. The verses describing the creation of humans also point to this transformation (Surah Al-Hajj, 22:5; Surah Al-Qiyamah, 75:36-38; Surah Ghafir, 40:67; Surah Al-Mu’minun, 23:14). A human, created from impure matter, goes through many transformations before reaching a perfect form.
Therefore, claiming that impure or haram substances remain under the same ruling even after undergoing istihalah is practically unfeasible. This would impose an unrealistic burden of investigating the original states of all substances we come into contact with, which would be an overwhelming and impossible task. Thus, it must be accepted that when the fundamental structure of a substance changes, along with its associated properties such as color, taste, and smell, its ruling also changes.