God has revealed the best of discourses a Book kitāban substitutes for ahsana ‘the best’ namely a Qur’ān consimilar in other words some of its parts are similar to others in terms of their arrangement and otherwise in coupled phrases — a Book in which the Promise of reward is coupled with the Threat of punishment together with other such couplings — whereat quiver at the mention of whose Threat shiver the skins of those who fear their Lord; then their skins and their hearts soften to they are reassured by the remembrance of God that is at the mention of His Promise. That Book is God’s guidance by which He guides whomever He will of His servants; and whomever God leads astray for him there is no guide.