Why study historical legal documents in an Islamic law perspective?

Why study historical legal documents in an Islamic law perspective?



The answer depends on our vision on Islamic law:


1) as unchanging and sacred set of norms that existed from early on, or


2) as the jurists' interpretation of Islamic normativity that grew over centuries and became a normative referent for the law in Muslim societies. 


In the first case, the study of legal documents has no impact on "Islamic law". In the second case, legal documents may reflect juridical practice in Muslim societies - and legal change.