Allah the Exalted states that the hypocrites pretended to be Muslims when they went to the Prophet . In reality, they were not Muslims, but rather the opposite. This is why Allah the Exalted said,

[إِذَا جَآءَكَ الْمُنَـفِقُونَ قَالُواْ نَشْهَدُ إِنَّكَ لَرَسُولُ اللَّهِ]

(When the hypocrites come to you, they say: "We bear witness that you are indeed the Messenger of Allah.'') meaning, `when the hypocrites come to you, they announce this statement and pretend to believe in it.' Allah informs that there is no substance to their statement, and this is why He said,

[وَاللَّهُ يَعْلَمُ إِنَّكَ لَرَسُولُهُ]

(Allah knows that you are indeed His Messenger,) then said,

[وَاللَّهُ يَشْهَدُ إِنَّ الْمُنَـفِقِينَ لَكَـذِبُونَ]

(And Allah bears witness that the hypocrites are liars indeed.) meaning, their claims, even though it is true about the Prophet. But they did not believe inwardly in what they declared outwardly, and this is why Allah declared their falsehood about their creed. Allah's statement,

[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 shield themselves from Muslims when they falsely and sinfully swear to be what they are not in reality. Some Muslims were deceived because they did not know their falsehood, and thus, thought that they were Muslims. Some Muslims believed what hypocrites say and even imitated them in their outward behavior. However, inwardly, hypocrites seek the destruction of Islam and its people, and this is why trusting them might bring great harm to many people. This is why Allah said next,

[فَصَدُّواْ عَن سَبِيلِ اللَّهِ إِنَّهُمْ سَآءَ مَا كَانُواْ يَعْمَلُونَ]

(Thus they hinder (others) from the path of Allah. Verily, evil is what they used to do.) Allah said,

[ذَلِكَ بِأَنَّهُمْ ءَامَنُواّ ثُمَّ كَفَرُوا فَطُبِعَ عَلَى قُلُوبِهِمْ فَهُمْ لاَ يَفْقَهُونَ ]

(That is because they believed, and then disbelieved; therefore their hearts are sealed, so they understand not.) meaning, He has decreed them to be hypocrites because they reverted from faith to disbelief and exchanged guidance for misguidance. Therefore, Allah stamped and sealed their hearts and because of it, they cannot comprehend the guidance, nor any goodness can reach their hearts. Truly, their hearts neither understand, nor attain guidance. Allah said,

[وَإِذَا رَأَيْتَهُمْ تُعْجِبُكَ أَجْسَـمُهُمْ وَإِن يَقُولُواْ تَسْمَعْ لِقَوْلِهِمْ]

(And when you look at them, their bodies please you; and when they speak, you listen to their words.) meaning, hypocrites have a graceful outer appearance and are eloquent. When one hears them speak, he will listen to their eloquent words, even though hypocrites are truly weak and feeble, full of fear, fright and cowardice. Allah's statement,

[يَحْسَبُونَ كُلَّ صَيْحَةٍ عَلَيْهِمْ]

(They think that every cry is against them.) means, every time an incident occurs or something frightening happens, they think that it is headed their way. This is indicative of their cowardice, just as Allah said about them,

[أَشِحَّةً عَلَيْكُمْ فَإِذَا جَآءَ الْخَوْفُ رَأَيْتَهُمْ يَنظُرُونَ إِلَيْكَ تَدورُ أَعْيُنُهُمْ كَالَّذِى يُغْشَى عَلَيْهِ مِنَ الْمَوْتِ فَإِذَا ذَهَبَ الْخَوْفُ سَلَقُوكُم بِأَلْسِنَةٍ حِدَادٍ أَشِحَّةً عَلَى الْخَيْرِ أوْلَـئِكَ لَمْ يُؤْمِنُواْ فَأَحْبَطَ اللَّهُ أَعْمَـلَهُمْ وَكَانَ ذَلِكَ عَلَى اللَّهِ يَسِيراً ]

(Being miserly towards you then when fear comes, you will see them looking to you, their eyes revolving like (those of) one over whom hovers death; but when the fear departs, they will smite you with sharp tongues, miserly towards good. Such have not believed. Therefore Allah makes their deeds fruitless and that is ever easy for Allah.) (33:19) They are shapes that do not have much substance, and this is why Allah said,

[هُمُ الْعَدُوُّ فَاحْذَرْهُمْ قَاتَلَهُمُ اللَّهُ أَنَّى يُؤْفَكُونَ]

(They are the enemies, so beware of them. May Allah curse them! How are they denying the right path) means, how they are being led astray to the misguidance, away from the guidance. Imam Ahmad recorded that Abu Hurayrah said that the Prophet said,

«إِنَّ لِلْمُنَافِقِينَ عَلَامَاتٍ يُعْرَفُونَ بِهَا: تَحِيَّتُهُمْ لَعْنَةٌ وَطَعَامُهُمْ نُهْبَةٌ وَغَنِيمَتُهُمْ غُلُولٌ لَا يَقْرَبُونَ الْمَسَاجِدَ إِلَّا هَجْرًا، وَلَا يَأْتُونَ الصَّلَاةَ إِلَّا دَبْرًا، مُسْتَكْبِرِينَ لَا يَأْلَفُونَ وَلَا يُؤْلَفُونَ، خُشُبٌ بِاللَّيْلِ صُخُبٌ بِالنَّهَارِ وفِي رِوَايَةٍ سُخُبٌ بِالنَّهَار»

(Hypocrites have certain signs that they are known by. Their greeting is really a curse, their food is from stealing and the war booty they collect is from theft. They shun the Masjid and they do not come to the prayer but at its end. They are arrogant; it is neither easy for them to blend in, nor it is easy for people to blend with them. They are like pieces of wood by night and are noisy by day.)

[وَإِذَا قِيلَ لَهُمْ تَعَالَوْاْ يَسْتَغْفِرْ لَكُمْ رَسُولُ اللَّهِ لَوَّوْاْ رُءُوسَهُمْ وَرَأَيْتَهُمْ يَصُدُّونَ وَهُم مُّسْتَكْبِرُونَ - سَوَآءٌ عَلَيْهِمْ أَسْتَغْفَرْتَ لَهُمْ أَمْ لَمْ تَسْتَغْفِرْ لَهُمْ لَن يَغْفِرَ اللَّهُ لَهُمْ إِنَّ اللَّهَ لاَ يَهْدِى الْقَوْمَ الْفَـسِقِينَ - هُمُ الَّذِينَ يَقُولُونَ لاَ تُنفِقُواْ عَلَى مَنْ عِندَ رَسُولِ اللَّهِ حَتَّى يَنفَضُّواْ وَلِلَّهِ خَزَآئِنُ السَّمَـوَتِ وَالاٌّرْضِ وَلَـكِنَّ الْمُنَـفِقِينَ لاَ يَفْقَهُونَ - يَقُولُونَ لَئِن رَّجَعْنَآ إِلَى الْمَدِينَةِ لَيُخْرِجَنَّ الاٌّعَزُّ مِنْهَا الاٌّذَلَّ وَلِلَّهِ الْعِزَّةُ وَلِرَسُولِهِ وَلِلْمُؤْمِنِينَ وَلَـكِنَّ الْمُنَـفِقِينَ لاَ يَعْلَمُونَ ]

(5. And when it is said to them: "Come, so that the Messenger of Allah may ask forgiveness from Allah for you,'' they twist their heads, and you would see them turning away their faces in pride.) (6. It is equal to them whether you ask forgiveness or ask not forgiveness for them, Allah will never forgive them. Verily, Allah guides not the people who are the rebellious.) (7. They are the ones who say: "Spend not on those who are with Allah's Messenger, until they desert him.'' And to Allah belong the treasures of the heavens and the earth, but the hypocrites comprehend not.) (8. They say: "If we return to Al-Madinah, indeed the more honorable will expel therefrom the weaker.'' But Al-`Izzah belongs to Allah, and to His Messenger, and to the believers, but the hypocrites know not.)