Social Change
\r\nCustom (urf) which does not contravene the principles of Shariah is valid and authoritative; it must be observed and upheld by a court of law. According to a legal maxim which is recorded by the Shafii jurist al-Suyuti, in his well-known work, al-Ashbah wa al-Nazair, 'What is proven by urf is like that which is proven by a shari proof.' This legal maxim is also recorded by the Hanafi jurist al-Sarakhsi, and was subsequently adopted in the Ottoman Majallah which provides that custom, whether general or specific, is enforceable and constitutes a basis of judicial decisions.
\r\nThe ulema have generally accepted urf as a valid criterion for purposes of interpreting the Quran. To give an example, the Quranic commentators have referred to urf in determining the precise amount of maintenance that a husband must provide for his wife. This is the subject of sura al-Talaq (65:7). In this ayah, the Quran does not specify the exact amount of maintenance, which is to be determined by reference to custom. Similarly, in regard to the maintenance of children, the Quran only specifies that this is the duty of the father, but leaves the quantum of maintenance to be determined by reference to custom (bil-maruf) (al-Baqarah, 2:233).
\r\nThe rules of fiqh which are based in juristic opinion (ray) or in speculative analogy and ijtihad have often been formulated in the light of prevailing custom; it is therefore, permissible to depart from them if the custom on which they were founded changes in the course of time. The ijtihad rules of fiqh are, for the most part, changeable with changes of time and circumstance. To deny social change due recognition in the determination of the rules of fiqh would amount to exposing the people to hardship, which the Shariah forbids. Sometimes even the same mujtahid has changed his previous ijtihad with a view to bringing it into harmony with the prevailing custom. It is well-known, for example, that Imam al-Shafi laid the foundations of his school in Iraq, but that when he went to Egypt, he changed some of his earlier views owing to the different customs he encountered in Egyptian society.
\r\nCompiled From:
\r\n \"Principles of Islamic Jurisprudence\" - Mohammad Hashim Kamali, p. 249