It is also well known that the ruling they were ordered to enforce from the ordinances of the Torah—one that the Gospel and the Quran did not abrogate—is matched by the rulings they were ordered to enforce from the Gospel, for these likewise have not been abrogated by the Quran. The comprehensive religion is to worship Allah alone, to command what Allah has commanded, and to judge according to whatever Allah has revealed in any scripture He has sent down so long as it has not been abrogated; such rulings must therefore be applied.
For this reason the position of the vast majority of the early Muslims (salaf) and the leading scholars is that the revealed law of those before us remains binding upon us unless our own law has come with something that contradicts it. Whoever judges by an abrogated law has not in fact judged