For further information regarding the functions of these angels refer to the books mentioned above.
وَ الَّذِينَ {لَا يَعْصُونَ اللَّهَ مَا أَمَرَهُمْ وَ يَفْعَلُونَ مَا يُؤْمَرُونَ} وَ الَّذِينَ يَقُولُونَ {سَلَامٌ عَلَيْكُمْ بِمَا صَبَرْتُمْ فَنِعْمَ عُقْبَى الدَّارِ} وَ الزَّبَانِيَةِ الَّذِينَ إِذَا قِيلَ لَهُمْ: {خُذُوهُ فَغُلُّوهُ * ثُمَّ الْجَحِيمَ صَلُّوهُ} ابْتَدَرُوهُ سِرَاعًا وَلَمْ يُنْظِرُوهُ وَ مَنْ أَوْهَمْنَا ذِكْرَهُ وَ لَمْ نَعْلَمْ مَكَانَهُ مِنْكَ وَ بِأَيِّ أَمْرٍ وَكَّلْتَهُ
“O God send Your blessings to those angels who are obedient and are not negligent towards their duties.
And send Your blessings as well to those angels who tell the believers in the Hereafter: Peace be on you for your perseverance in worshipping Allah and for your refraining from getting involved in doing mischief.
And send Your blessings to those angels who perform the roles of police in capturing the criminals and taking them towards the hell.
And send Your blessings to that unknown angel of Yours whose duties we are not able to comprehend.”
The expression وَالّذِينَ لايَعْصُونَ “those who are not negligent of their duties,” refers to the sixth verse of the sacred surah Tahrim (The prohibition, Qur’an 66:6).
يَا أَيُّهَا الَّذِينَ آمَنُوا قُوا أَنفُسَكُمْ وَأَهْلِيكُمْ نَارًا وَقُودُهَا النَّاسُ وَالْحِجَارَةُ عَلَيْهَا مَلَائِكَةٌ غِلَاظٌ شِدَادٌ لَا يَعْصُونَ اللَّهَ مَا أَمَرَهُمْ وَيَفْعَلُونَ مَا يُؤْمَرُونَ
“O you who believe! Save yourselves and your families from a fire whose fuel is men and stones; over it are angels stern and strong, they do not disobey Allah in what He commands them, and do as they are commanded.”
In the expression قُوا أَنفُسَكُمْ “Save your-selves” God commands us to save ourselves from the fire of chastisement by our perseverance in avoiding committing mischief.
In the expression أَهْلِيكُمْ “Your families” God commands us to save our-selves and our families from involving in evil. He orders us to encourage our subordinates to stay away from the Hell Fire.
The expression وَالَّذينَ يَقُولُونَ سَلامٌ refers to the verses 20 to 24 of the sacred surah of Ra’d (Qur’an 13:20-24): Those who fulfill the promise of Allah and do not break the covenant, and those who join that which Allah has bidden to be joined and have awe of their Lord and fear the evil reckoning. And those who are constant, seeking the pleasure of their Lord, and keep up prayer and spend benevolently out of what We have given them secretly and openly and repel evil with good, as for those, they shall have the happy issue of the abode, the gardens of perpetual abode which they will enter along with those who do good from among their parents and their spouses and their offspring; and the angels will enter in upon them from every gate: Peace be on you because you were constant, how excellent, is then, the issue of the abode.
The expression خُذُوهُ فَغُلُّوهُ refers to the verses 30-34 of the sacred surah Haqqah(Qur’an 69:30-34):
خُذُوهُ فَغُلُّوهُ ثُمَّ الْجَحِيمَ صَلُّوهُ ثُمَّ فِي سِلْسِلَةٍ ذَرْعُهَا سَبْعُونَ ذِرَاعًا فَاسْلُكُوهُ إِنَّهُ كَانَ لَا يُؤْمِنُ بِاللَّهِ الْعَظِيمِ وَلَا يَحُضُّ عَلَى طَعَامِ الْمِسْكِينِ
“Lay hold on him, then put a chain on him, then cast him into the burning fire; then thrust him into a chain the length of which is seventy cubits. Surely he did not believe in Allah, the Great. Nor did he urge the feeding of the poor.
* * * *
وَ سُكَّانِ الْهَوَآءِ وَ الْأَرْضِ وَالْمَآءِ وَ مَنْ مِنْهُمْ عَلَى الْخَلْقِ فَصَلِّ عَلَيْهِمْ يَوْمَ تَأْتِي كُلُّ نَفْسٍ مَعَهَا سَآئِقٌ وَشَهِيدٌ وَصَلِّ عَلَيْهِمْ صَلَاةً تَزِيدُهُمْ كَرَامَةً عَلَى كَرَامَتِهِمْ وَ طَهَارَةً عَلَى طَهَارَتِهِمْ اللَّهُمَّ وَ إِذَا صَلَّيْتَ عَلَى مَلَآئِكَتِكَ وَرُسُلِكَ وَ بَلَّغْتَهُمْ صَلَاتَنَا عَلَيْهِمْ فَصَلِّ عَلَيْهِمْ بِمَا فَتَحْتَ لَنَا مِنْ حُسْنِ الْقَوْلِ فِيهِمْ إِنَّكَ جَوَادٌ كَرِيمٌ.
“O God! Send Your blessings to those angels of yours who live in the air, on the earth and in the water. Send Your blessings, as well, to those angels of yours who have been appointed by You to control Your creatures. Send Your blessings to those angels who accompany each human being on the Doom’s Day, one angel leading him to the place of trial, the other angel being his witness. This is explicitly stated in the Holy Qur’an:
وَجَاءَتْ كُلُّ نَفْسٍ مَعَهَا سَائِقٌ وَشَهِيدٌ [1]
“And every soul shall come, with it a driver and a witness.”
source : The Book: Diar Aashiqan by prof, Hussain Ansarian