Why don't Shar'i rulings change to keep pace with contemporary variables, such as the prohibition of usury and the hijab, even though some rulings changed in the past?

Islamic Sharia (definition) is characterized by the constancy of its fundamental principles and the variability of its subsidiary rulings. Sharia rulings are divided into constants and variables:

1. Constants: These include beliefs and monotheism, the general objectives of Sharia (Maqasid al-Sharia), universal jurisprudential rules, legislative values, consensus (ijma‘), and specific issues related to benefits or harms that are inseparable in any time or place, such as the obligation of hijab (definition). These constants do not change with the change of time and place.

2. Variables: These are ijtihadi (derived through independent reasoning) rulings that are based on custom (urf) or interest (maslaha) and are affected by changes in time, place, customs, circumstances, and intentions, such as some branches of financial transactions. This flexibility allows Sharia to adapt to new developments without compromising its constants.

Islamic jurisprudence is renewed by applying Sharia rulings to changing circumstances according to the realization of their underlying basis (manat), while preserving the fundamental Sharia principles.