A whole chapter in Quran is their By name itself. MUNAFIQOON. Chapter 63

What a beauty and significance of Quran you ask to it it answers any thing. ALLAHU AKBER. It is nothing but a instruction manual from the creator ALLAH Subhana wa taala.

إِذَا جَاءَكَ الْمُنَافِقُونَ قَالُوا نَشْهَدُ إِنَّكَ لَرَسُولُ اللَّـهِ ۗ وَاللَّـهُ يَعْلَمُ إِنَّكَ لَرَسُولُهُ وَاللَّـهُ يَشْهَدُ إِنَّ الْمُنَافِقِينَ لَكَاذِبُونَ ﴿١﴾ اتَّخَذُوا أَيْمَانَهُمْ جُنَّةً فَصَدُّوا عَن سَبِيلِ اللَّـهِ ۚ إِنَّهُمْ سَاءَ مَا كَانُوا يَعْمَلُونَ﴿٢﴾ ذَٰلِكَ بِأَنَّهُمْ آمَنُوا ثُمَّ كَفَرُوا فَطُبِعَ عَلَىٰ قُلُوبِهِمْ فَهُمْ لَا يَفْقَهُونَ ﴿٣﴾ وَإِذَا رَأَيْتَهُمْ تُعْجِبُكَ أَجْسَامُهُمْ ۖ وَإِن يَقُولُوا تَسْمَعْ لِقَوْلِهِمْ ۖ كَأَنَّهُمْ خُشُبٌ مُّسَنَّدَةٌ ۖ يَحْسَبُونَ كُلَّ صَيْحَةٍ عَلَيْهِمْ ۚهُمُ الْعَدُوُّ فَاحْذَرْهُمْ ۚ قَاتَلَهُمُ اللَّـهُ ۖ أَنَّىٰ يُؤْفَكُونَ ﴿٤

وَإِذَا قِيلَ لَهُمْ تَعَالَوْا يَسْتَغْفِرْ لَكُمْ رَسُولُ اللَّـهِ لَوَّوْا رُءُوسَهُمْ وَرَأَيْتَهُمْ يَصُدُّونَ وَهُم مُّسْتَكْبِرُونَ ﴿٥﴾ سَوَاءٌ عَلَيْهِمْ أَسْتَغْفَرْتَ لَهُمْ أَمْ لَمْ تَسْتَغْفِرْ لَهُمْ لَن يَغْفِرَ اللَّـهُ لَهُمْ ۚ إِنَّ اللَّـهَ لَا يَهْدِي الْقَوْمَ الْفَاسِقِينَ ﴿٦﴾ هُمُ الَّذِينَ يَقُولُونَ لَا تُنفِقُوا عَلَىٰ مَنْ عِندَ رَسُولِ اللَّـهِ حَتَّىٰ يَنفَضُّوا ۗ وَلِلَّـهِ خَزَائِنُ السَّمَاوَاتِ وَالْأَرْضِ وَلَـٰكِنَّ الْمُنَافِقِينَ لَا يَفْقَهُونَ ﴿٧﴾ يَقُولُونَ لَئِن رَّجَعْنَا إِلَى الْمَدِينَةِ لَيُخْرِجَنَّ الْأَعَزُّ مِنْهَا الْأَذَلَّ ۚ وَلِلَّـهِ الْعِزَّةُ وَلِرَسُولِهِ وَلِلْمُؤْمِنِينَ وَلَـٰكِنَّ الْمُنَافِقِينَ لَا يَعْلَمُونَ ﴿٨﴾

When the hypocrites come to you, they say: "We bear witness that you are indeed the Messenger of Allah." Allah knows that you are indeed His Messenger, and Allah bears witness that the hypocrites are liars indeed. (1)

They have made their oaths a screen. Thus they hinder (others) from the path of Allah. Verily, evil is what they used to do. (2) That is because they believed, and then disbelieved; therefore their hearts are sealed, so they understand not. (3) And when you look at them, their bodies please you; and when they speak, you listen to their words. They are as blocks of wood propped up. They think that every cry is against them. They are the enemies, so beware of them. May Allah curse them! How are they denying the right path (4)

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. (5) 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.(6) 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. (7) 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. (8)