What is “Hashr and Nashr”?
“Nashr” means to resurrect the creation after death; “Hashr” means to take them towards the plain of Judgement and then towards Paradise and Hell. (Al-Musamirah ba-Sharh Al-Musa`eerah, pp. 250)
Ruling for the denier
The belief of “Hashr and Nashr” lies in the category of Zaruriyat-e-Deen. There is Ijma’ [consensus] of Ummah on this belief that the denier of “Hashr and Nashr” is a Kafir [unbeliever]. (Al-Mu’taqid-ul-Muntaqid ma’ Al-Mu’tamid, pp. 327; summarized)
Whose Hashr will take place?
Hashr will not be only of the soul; in fact, it will be of both, soul and body. The one who believes that only souls will be raised and the bodies will not be resurrected is also a Kafir. The Hashr of the soul will be in the same body to which it was related in this world. It is not the case that any new body will be created and its connection will be made with the soul. (Bahar-e-Shari’at, vol. 1, pp. 130)
People whom beasts have eaten
Even if the constituents of the body have spread after the death or [the constituents] have been eaten by different animals, Allah عَزَّوَجَلَّ will gather all those constituents and resurrect on the Day of Judgement. (Bahar-e-Shari’at, vol. 1, pp. 130; summarized)
Will everyone be undressed?
The Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم has stated: On the Day of Judgement, people will be raised from their graves undressed, barefooted and uncircumcised. (Sahih Muslim, pp. 1172, Hadees 7198)
Remember! This saying is related to Ummah, which clearly indicates that the blessed Ambiya (عَـلَـيْهِمُ السَّلَام) are all exempt [from it]; by the grace of Allah عَزَّوَجَلَّ, all of them will be dressed. (Fatawa Nooriyah, vol. 5, pp. 125)
Sayyiduna Imam Bayhaqi رَحْمَةُ اللهِ تَعَالٰی عَلَيْه has mentioned the following reconciliation of different narrations: Some people will be undressed whereas some people will be dressed. (Tafseer Mazhari, Al-A’raf, Taht-al-Ayah: 29, vol. 3, pp. 363)
The great Faqeeh [Islamic jurist], ‘Allamah Mufti Muhammad Noorullah Na’eemi رَحْمَةُ اللهِ تَعَالٰی عَلَيْه has stated: All the blessed Sahabah and great Awliya will also be dressed. Moreover, Shaheed [martyrs] and chosen Mu’mineen will be dressed. (For details, please read: Fatawa Nooriyah, volume 5, page 129; summarized)
Condition of the people in Hashr
Sayyiduna ‘Allamah Ibraheem Bayjauri رَحْمَةُ اللهِ تَعَالٰی عَلَيْه has stated, ‘The status of the people will be different in Hashr: The pious people will be riding, people having some deeds will be [walking] on foot whereas the Kafir [unbelievers] will be walking on their faces.’ (Tohfa-tul-Mureed, pp. 407)
It was asked from the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم: ‘How will the Kafir walk on their faces?’ The Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم responded: ‘The One Who made them walk on [their] feet is Powerful to make them walk on their faces as well.’ (Sunan-ut-Tirmizi, vol. 5, pp. 96, Hadees 3153)
The angels will take some people by dragging [them]; fire will gather some people (i.e. it will take them to the plain of Judgement). (Bahar-e-Shari’at, vol. 1, pp. 131)
Before anyone else
Our Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم will come out from the blessed grave before anyone else in such a way that he will be holding the hand of Sayyiduna Siddeeq-e-Akbar رَضِىَ اللهُ تَعَالٰی عَـنْهُ in his right hand and the hand of Sayyiduna Farooq-e-A’zam رَضِىَ اللهُ تَعَالٰی عَـنْهُ in his left hand. (Sunan-ut-Tirmizi, vol. 4, pp. 378, Hadees 3689)
He صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم will then go to the plain of Judgement, taking all the Muslims who are buried in the graveyards of Makkah Mukarramah and Madinah Tayyibah. (Sunan-ut-Tirmizi, vol. 5, pp. 388, Hadees 3712)
Then, the people of Shaam (Syria) and other people will come out from their graves. (Sharh-us-Saawi ‘ala Jawhira-tut-Tawheed, pp. 373)
Where will Hashr take place?
This plain of Judgement will be located on the land of Shaam (Syria). The land will be so smooth that if a mustard seed drops at one end, it can be seen from the other end. (Bahar-e-Shari’at, vol. 1, pp. 132)
The earth will be changed
It is stated in the Holy Quran:
یَوْمَ تُبَدَّلُ الْاَرْضُ غَیْرَ الْاَرْضِ وَ السَّمٰوٰتُ
Translation from Kanz-ul-Iman: On the Day when the earth will be changed to other than this earth, and the heavens too. (Part 13, Surah Ibraheem, Ayah 48)
Regarding the different sayings mentioned in Tafseer of this blessed Ayah, Imam Jalaluddin ‘Abdur Rahman Suyuti رَحْمَةُ اللهِ تَعَالٰی عَلَيْه has narrated from Haafiz Ibn Hajar ‘Asqalani رَحْمَةُ اللهِ تَعَالٰی عَلَيْه: There is no contradiction between the earth becoming Roti [a type of unleavened bread], dusty and fire which has been mentioned in Ahadees. In fact, reconciliation of all these sayings can be made in this way: Some pieces of earth will become Roti, some will become dust and some will become fire. Moreover, the saying that earth will become fire is specifically related to the [area of] earth covering the sea (i.e. the area of earth covering the sea will become of fire). (Al-Budoor-us-Saafirah, pp. 53)
It is mentioned in Tafseer Mazhari: Maybe the place beneath the feet of Mu’mineen will become Roti and the place beneath the feet of Kuffar will become dusty and fiery. (Tafseer Mazhari, Ibraheem, Taht-al-Ayah: 48, vol. 5, pp. 149)
 Zaruriyat-e-Deen refers to those fundamental Islamic beliefs and practices which are known by all the ‘Ulama [Islamic scholars] and common people [close to ‘Ulama]. For example, Oneness of Allah عَزَّوَجَلَّ, Nubuwwah of blessed Ambiya عَـلَـيْهِمُ السَّلَام, Salah, Siyam [fasts], Hajj, Jannah, Hell, resurrection on the Day of Judgement, accountability, etc.