Allah chastises the hypocrites for secretly aiding and supporting the disbelievers even though, in reality, they were neither with the disbelievers nor with the Muslims. Allah the Exalted said in another Ayah,
مُّذَبْذَبِينَ بَيْنَ ذلِكَ لاَ إِلَى هَـؤُلاءِ وَلاَ إِلَى هَـؤُلاءِ وَمَن يُضْلِلِ اللَّهُ فَلَن تَجِدَ لَهُ سَبِيلاً
((They are) swaying between this and that, belonging neither to these nor to those; and he whom Allah sends astray, you will not find for him a way.)(4:143) Allah said here,
أَلَمْ تَرَ إِلَى الَّذِينَ تَوَلَّوْاْ قَوْماً غَضِبَ اللَّهُ عَلَيْهِم
(Have you not seen those who take as friends a people upon whom is the wrath of Allah) referring to the Jews with whom the hypocrites were allies in secret. Allah said,
مَّا هُم مِّنكُمْ وَلاَ مِنْهُمْ
(They are neither of you nor of them,) meaning, that these hypocrites are neither with the believers, nor with their allies the Jews,
وَيَحْلِفُونَ عَلَى الْكَذِبِ وَهُمْ يَعْلَمُونَ
(and they swear to a lie while they know.) meaning, the hypocrites lie when they vow, knowing that they are lying, which is called the vow of Al-Ghamus. We seek refuge with Allah from their ways. When the hypocrites met the believers they said that they believed and when they went to the Messenger, they swore to him by Allah that they were believers. They knew that they were lying in their vow, and they knew that they did not declare their true creed. This is why Allah witnessed here that they lie in their vows and know that they are lying, even though their statement (about the Prophet being Allah's Prophet) is true in essence. Allah the Exalted said,
أَعَدَّ اللَّهُ لَهُمْ عَذَاباً شَدِيداً إِنَّهُمْ سَآءَ مَا كَانُواْ يَعْمَلُونَ
(Allah has prepared for them a severe torment. Evil indeed is that which they used to do.) meaning, Allah has prepared a painful torment for the hypocrites on account of their evil deeds, their aid and support of the disbelievers and their deceit and betrayal of the believers. The statement of Allah the Exalted,
اتَّخَذْواْ أَيْمَـنَهُمْ جُنَّةً فَصَدُّواْ عَن سَبِيلِ اللَّهِ
(They have made their oaths a screen. Thus they hinder (others) from the path of Allah,) meaning, the hypocrites pretended to be believers and concealed disbelief under the shield of their false oaths. Many were unaware of their true stance and were thus deceived by their oaths. Because of this, some people were hindered from the Path of Allah
فَلَهُمْ عَذَابٌ مُّهِينٌ
(so they shall have a humiliating torment.) meaning, as recompense for belittling the significance of swearing by the Mighty Name of Allah, while lying and concealing betrayal. Allah the Exalted said,
لَن تُغْنِىَ عَنْهُمْ أَمْوَلُهُمْ وَلاَ أَوْلـدُهُم مِّنَ اللَّهِ شَيْئًا
(Their children and their wealth will avail them nothing against Allah.) meaning, none of their possessions can avert the affliction when it is sent their way,
أُولَـئِكَ أَصْحَـبُ النَّارِ هُمْ فِيهَا خَـلِدُونَ
(They will be the dwellers of the Fire to dwell therein forever.) Allah the Exalted said,
يَوْمَ يَبْعَثُهُمُ اللَّهِ جَمِيعاً
(On the Day when Allah will resurrect them all together;) referring to the Day of Resurrection when He will gather them all together and leave none of them out,
فَيَحْلِفُونَ لَهُ كَمَا يَحْلِفُونَ لَكُمْ وَيَحْسَبُونَ أَنَّهُمْ عَلَى شَىْءٍ
(then they will swear to Him as they swear to you. And they think that they have something.) meaning, they will swear to Allah the Exalted and Most Honored that they were following the guidance and the correct path, just as they used to swear to the believers in this worldly life. Verily, those who live following on a certain path will most likely die while on it. Thus, they will be resurrected upon their path. The hypocrites will think that their vows will help them with Allah, just as they helped with the people, who were obliged to treat them as they pretended to be, Muslim. This is why Allah said,
وَيَحْسَبُونَ أَنَّهُمْ عَلَى شَىْءٍ
(And they think that they have something) meaning, on account of swearing to their Lord (that they used to be believers). Allah rebukes this idea of theirs;
أَلاَ إِنَّهُمْ هُمُ الْكَـذِبُونَ
(Verily, they are liars!) stressing that they are lying, Allah then said;
اسْتَحْوَذَ عَلَيْهِمُ الشَّيْطَـنُ فَأَنسَـهُمْ ذِكْرَ اللَّهِ
(The Shaytan has overpowered them. So he has made them forget the remembrance of Allah.) meaning, Shaytan has taken over their hearts to the point that he made them forget Allah the Exalted and Most Honored. This is what the devil does to those whom he controls. Abu Dawud recorded that Abu Ad-Darda' said that he heard the Messenger of Allah ﷺ say,
«مَا مِنْ ثَلَاثَةٍ فِي قَرْيَةٍ وَلَا بَدْوٍ، لَا تُقَامُ فِيهِمُ الصَّلَاةُ إِلَّا قَدِ اسْتَحْوَذَ عَلَيْهِمُ الشَّيْطَانُ، فَعَلَيْكَ بِالْجَمَاعَةِ، فَإِنَّمَا يَأْكُلُ الذِّئْبُ الْقَاصِيَة»
(Any three in a village or desert among whom the Salah is not called for, will have the Shaytan control them. Therefore, adhere to the Jama`ah, for the wolf eats from the strayed sheep.) Za'idah added that As-Sa'ib said that Jama`ah, refers to, "Praying in congregation." Allah the Exalted said,
أُوْلَـئِكَ حِزْبُ الشَّيْطَـنِ
(They are the party of Shaytan.) referring to those who are controlled by the devil and, as a result, forgot the remembrance of Allah,
أَلاَ إِنَّ حِزْبَ الشَّيْطَـنِ هُمُ الخَـسِرُونَ
(Verily, it is the party of Shaytan that will be the losers!)