If they have a book of mine [source of reference] to justify their acts, let them bring it up [This indicates that morality of each society depends on its book of laws and what book of laws superior than the one of God]
Faridul Haque
Or have We given them some Book before this, to which they hold fast
Hasan Al-Fatih Qaribullah
Or have We given them a Book before this which they hold fast to