Muhammad Asad, The Message of the Qur’ān; Translated and Explained by Muhammad Asad (1980)
(8) And there are people who say, “We do believe in God and the Last Day,” the while they do not [really] believe. (9) They would deceive God and those who have attained to faith – the while they deceive none but themselves, and perceive it not. (10) In their hearts is disease, and so God lets their disease increase; and grievous suffering awaits them because of their persistent lying.8
(11) And when they are told, “Do not spread corruption on earth,” they answer, “We are but improving things!” (12) Oh, verily, it is they, they who are spreading corruption – but they perceive it not!9
(13) And when they are told, “Believe as other people believe, they answer, “Shall we believe as the weak-minded believe?” Oh, verily, it is they, they who are weak-minded - but they know it not!
(14) And when they meet those who have attained to faith, they assert, “We believe [as you believe]”; but when they find themselves alone with their evil impulses,10 they say, “Verily, we are with you; we were only mocking!”
(15) God will requite them for their mockery,11 and will leave them for a while in their overweening arrogance, blindly stumbling to and fro: (16) [for] it is they who have taken error in exchange for guidance;
God”) – this “sealing” is attributed to Him: but it is obviously a consequence of man's free choice and not an act of “predestination”. Similarly, the suffering which, in the life to come, is in store for those who during their life in this world have wilfully remained deaf and blind to the truth, is a natural consequence of their free choice – just as happiness in the life to come is the natural consequence of man’s endeavour to attain to righteousness and inner illumination. It is in this sense that the Qurʾanic references to God’s “reward” and “punishment” must be understood.
8 I.e., before God and man – and to themselves. It is generally assumed that the people to whom this passage alludes in the first instance are the hypocrites of Medina who, during the early years after the hijrah, outwardly professed their adherence to Islam while remaining inwardly unconvinced of the truth of Muḥammad’s message. However, as is always the case with Qurʾanic allusions to contemporary or historical events, the above and the following verses have a general, timeless import inasmuch as they refer to all people who are prone to deceive themselves in order to evade a spiritual commitment.
9 It would seem that this is an allusion to people who oppose any “intrusion” of religious considerations into the realm of practical affairs, and thus – often unwittingly, thinking that they are “but improving things” – contribute to the moral and social confusion referred to in the subsequent verse.
10 Lit., “their satans” (shayaṭīn, pl. of shayṭān). In accordance with ancient Arabic usage, this term often denotes people “who, through their insolent persistence in evildoing (tamarrud), have become like satans” (Zamakhsharī): an interpretation of the above verse accepted by most of the commentators. However, the term shayṭān – which is derived from the verb shaṭana, “he was [or “became”] remote [from all that is good and true]” (Lisān al-ʿArab, Tāj al-ʿArūs) – is often used in the Qurʾān to describe the “satanic” (i.e., exceedingly evil) propensities in man’s own soul, and especially all impulses which run counter to truth and morality (Rāghib).
11 Lit., “God will mock at them”. My rendering is in conformity with the generally accepted interpretation of this phrase.