Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(In their hearts is a disease), doubt, hypocrisy, conflict and darkness (so Allah increaseth their disease), increased their doubt, hypocrisy, conflict and darkness. (And a painful doom is theirs), they will have a painful torment in the Hereafter which shall extend to their hearts, (because they lie) in secret, the reference here being to the hypocrites: 'Abdullah ibn Ubayy, Jadd Ibn Qays and Mu'attib Ibn Qushayr.
In their hearts is a sickness: doubt and hypocrisy, which ails their hearts, debilitating them; and God has increased their sickness with what He has revealed in the Qur’ān, since they disbelieve it; and there awaits them a painful chastisement because they used to lie (read yukadhdhibūn to imply [that they used to call] the Prophet of God [a liar], or yakdhibūn to imply their [mendacity when] saying ‘we believe’).
In their hearts is a sickness, in other words, doubt and hypocrisy. The use of the indefinite form of maraḍ (sickness) and the adverbial clause is an indication of the fact that [such a] sickness has befallen them and has established itself and taken root in these [hearts of theirs, as we have mentioned in the above structure, for otherwise He would have said: 'Their hearts are sick or [that they are] dead'; and God has increased them in sickness, that is, [with] another [sickness]: [God increases their] spite, envy and rancour by exalting the word of religion and the granting of assistance to the Messenger and the believers. All despicable acts are sicknesses of the heart as they are cause of its weakening and the evil of its private actions and its ruin in the final issue. He distinguishes between the two chastisements by [stipulating] pain for the hypocrites and an awesome [chastisement] for disbelievers, because the chastisement for those who have been banished from pre-eternity is greater. Thus they do not experience the intensity of its painfulness because of the impurity of their hearts' perception, similar to the state of a dead or hemiplegic or numbed limb [that senses nothing] when it undergoes severing or cauterisation and other kinds of pain. As for the hypocrites, they sense the extreme pain because of their established preparedness [for belief] at the outset and the permanence of their [faculties of] perception. Inevitably then their chastisement is painful, caused as it is by the chronic sickness that occurs [in their hearts], namely, mendacity and its [evil] concomitants.
and there awaits them a painful chastisement because they used to lie.
As-Suddi narrated from Abu Malik and (also) from Abu Salih, from Ibn `Abbas, and (also) Murrah Al-Hamdani from Ibn Mas`ud and other Companions that this Ayah,
فِى قُلُوبِهِمْ مَّرَضٌ
(In their hearts is a disease) means, `doubt', and,
فَزَادَهُمُ اللَّهُ مَرَضًا
(And Allah has increased their disease) also means `doubt'. Mujahid, `Ikrimah, Al-Hasan Al-Basri, Abu Al-`Aliyah, Ar-Rabi` bin Anas and Qatadah also said similarly. `Abdur-Rahman bin Zayd bin Aslam commented on,
فِى قُلُوبِهِمْ مَّرَضٌ
(In their hearts is a disease), "A disease in the religion, not a physical disease. They are the hypocrites and the disease is the doubt that they brought to Islam.
فَزَادَهُمُ اللَّهُ مَرَضًا
(And Allah has increased their disease) meaning, increased them in shameful behavior.'' He also recited,
(As for those who believe, it has increased their faith, and they rejoice. But as for those in whose hearts is a disease, it will add disgrace to their disgrace.) (9:124-125) and commented, "Evil to their evil and deviation to their deviation.'' This statement by `Abdur-Rahman is true, and it constitutes a punishment that is compatible to the sin, just as the earlier scholars stated. Similarly, Allah said,
(While as for those who accept guidance, He increases their guidance and grants them their piety) (47:17).
Allah said next,
بِمَا كَانُواْ يَكْذِبُونَ
(Because they used to tell lies). The hypocrites have two characteristics, they lie and they deny the Unseen.
The scholars who stated that the Prophet knew the hypocrites of his time have only the Hadith of Hudhayfah bin Al-Yaman as evidence. In it the Prophet gave him the names of fourteen hypocrites during the battle of Tabuk. These hypocrites plotted to assassinate the Prophet during the night on a hill in that area. They planned to excite the Prophet's camel, so that she would throw him down the hill. Allah informed the Prophet about their plot, and the Prophet told Hudhayfah their names.
As for the other hypocrites, Allah said about them,
(If the hypocrites, and those in whose hearts is a disease, and those who spread false news among the people in Al-Madinah do not cease, We shall certainly let you overpower them, then they will not be able to stay in it as your neighbors but a little while. Accursed, they shall be seized wherever found, and killed with a (terrible) slaughter) (33:60-61).
These Ayat prove that the Prophet was not informed about each and everyone among the hypocrites of his time. Rather, the Prophet was only informed about their characteristics, and he used to assume that some people possessed these characteristics. Similarly, Allah said,
(Had We willed, We could have shown them to you, and you should have known them by their marks; but surely, you will know them by the tone of their speech!) (47:30).
The most notorious hypocrite at that time was `Abdullah bin Ubayy bin Salul; Zayd bin Arqam - the Companion - gave truthful testimony to that effect. In addition, `Umar bin Al-Khattab once mentioned the matter of Ibn Salul to the Prophet, who said,
(If I knew that by asking (Allah to forgive Ibn Salul) more than seventy times that He would forgive him, then I would do that.)
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
They deceive themselves by imagining that their duplicity will safeguard their interests but obviously their policy will prove harmful in this world as well as in the next. A hypocrite might succeed in deceiving some people for some time but he cannot deceive all people for all times. When such a person is exposed, he loses all honour once and for all. As to the Hereafter, mere lip-service will carry no weight there because it is deeds alone that matter there.
"A disease": the disease of hypocrisy; and "Allah is increasing their disease all the more" means that He does not punish the hypocrites for their hypocrisy immediately, but gives them respite so that when their duplicity appears to succeed apparently they become more and more convinced of its efficiency and they go on becoming more and more hypocritical in their attitude and conduct.
That is,"Just as the other people of your nation have accepted Islam truly and sincerely, so should you also accept it truly and honestly, if you profess to accept it".
They regarded as tools the people who had accepted Islam sincerely and exposed themselves to troubles, hardships and dangers. In their opinion it was nothing but folly to earn the hostility of the whole country merely for the sake of truth and righteousness. They considered it wisdom not to bother about the right and the wrong at all but to look only after one's own interests.
Shayatin plural of Shaitan, is an insurgent, haughty and devilish person, or an evil genius. This word is used both for the men and the jinn. Though it has mostly been used in the Qur'an for the jinn devils, in some places it has also been applied to human devils, and from the context it can easily be judged where it refers to human and where to jinn devils. Here it refers to the Arab chiefs who were in the fore-front in their opposition to Islam.
In their hearts is a sickness; and God has increased their sickness; and there awaits them a painful chastisement because they used to lie. In the hearts of the hypocrites is the sickness of making partners [with God] shirk and God increases their sickness in their imagining that they have been saved by deceiving the Muslims. The pain of their grievous punishment will reach them in the end. The allusion pertains to whoever has confused his ultimate objective qaṣd with his worldly concerns ḥaẓẓ and mixed his spiritual desire irāda with his whims hawā taking one step forward with spiritual desire and one step backward with worldly concerns and following the lower self. He is neither a sincere seeker murīd nor permanently neglectful. If the hypocrites had been sincere in their beliefs they would have been safe from the punishment in the hereafter just as they were safe from paying the jizya tax and the like in this world in the manner of polytheists and dhimmīs. Similarly if the seeker murīd had been sincere in his spiritual desire he would have reached out in his heart to the realities of the communion [of lovers] and the blessings of sincerity would have reached him and he [would have] attained what he desired. But his state is as it has been said: We have not been firm but justice will be firm with us without bending. If we had been sincere khalaṣnā we would have been saved takhallaṣnā from tribulation. There is a barrier between one whose worship has become weak and the degrees of the gardens darajāt al-jannāt. There is a barrier between one whose spiritual desire has become weak and the intimate communications of nearness and whispered confidences muwāṣalāt al-qurb wa-l-munājāt. As for those who rely on this world and follow [their] whims their reliance on the abode of illusion is an illness of their hearts. The increase in their disease will increase as their greed increases. The more they find something from [this world] the more their greed multiplies for what they have not found hastening the punishment for them. Among [their] immediate punishments are the dissipation of their aims and then the loss of all pleasure in their lives. They are kept by [these punishments] from their Protector mawlā. There will be no enjoyment for them nor rest in what they have preferred when [they] follow their own whims.
This is the requital for anyone who abandons the companionship of his Protector. It is said regarding this: She changed and we changed. Alas to anyone who has sought but did not find a replacement to let him forget. The allusion in [the words] the painful chastisement because they used to lie is to the grief on the Day of Unveiling when they see how those like them who were sincere ṣadaqū have arrived waṣalū and they see themselves and how they have lost khasirū.