Moreover, because of their duplicity, they dissemble when saying this, also. For outwardly they say: "How should we be like the weak-minded, for we aren't mad? We are as superior as you could wish." While inwardly they say: "How could we be like the believers, for most of them are paupers? In our eyes they are the dim-witted rabble of different nations."

You can now supply the fine points to the two parts of this conditional sentence.

The Qur'an then hurls back at them the stone they flung at the believers, ramming it down their throats: "Oh, verily, it is they, they who are weak-minded (a Iâ innahum hum al-sufahâ')." For whoever is obstinate to this degree and ignorant without realizing it, deserves to be paraded among the people and proclaimed the feeble-minded one, for this is an established fact, and their calling the believers weak-minded is due to their own feeblemindedness.

Then by saying: "but they know it not (wa lâkin lâ ya'lamûn)," it is pointing out that their ignorance is compounded because they are unaware of it. It is therefore useless to offer them advice; they should be shunned entirely. For it is only those who realize that they are ignorant that may benefit from advice.

The positioning of [and relationships between] the phrases' parts:

"And when they are told, 'Believe as other people believe(Wa idhâ qîla la-hum âminû ka-mâ âmana al-nâs):"

In this phrase, the certainty expressed by the word "when (idhâ)" indicates the necessity of offering guidance [to the people] by 'enjoining what is lawful.'

"[Being] told (qîla):" the passive mood infers that offering advice is an obligation [that may be performed by a number of people in the name of the community ('alâ sabîl al-kifâya)], as has been mentioned.

The use of the verb "believe (âminu)" rather than 'be sincere in your belief (akhlisû fi Imânikum) indicates that insincere belief is not belief.

The phrase "as [others] believe (ka-mâ âmana)" is an allusion to the fine examples of admirable men, suggesting that sincerity may be attained by following them.