The people of Paradise will not enter Paradise until they are cleansed of the injustices of the world

It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "After crossing the Sirat, the people of Paradise will be held back on a bridge (qantarah), and retribution will be taken among them for the wrongs that took place between them in the world, until, when they have become completely cleansed and purified, they will be given permission to enter Paradise. Then each one of them will know his abode in the Hereafter better than he knew his home in the world." Qatadah (may Allah have mercy on him) said that Abu Ubaydah bin Abdullah bin Mas'ud (may Allah have mercy on him) said: Their state will be just like those returning from the Friday prayer.
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Abdullah bin Amr bin al-As (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) recited this verse: "The Day when mankind will stand before the Lord of the worlds" [Surah al-Mutaffifin: 6], then the Messenger of Allah (peace and blessings be upon him) said: "What will be your state when Allah gathers you for fifty thousand years (in such confinement) just as arrows are gathered in a quiver, and then Allah will not look at you (with the look of mercy)?"
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Zubayr bin al-Awwam (may Allah be pleased with him) that when this verse and this surah were revealed to the Messenger of Allah (peace and blessings be upon him): "Indeed, you are to die, and indeed, they are to die. Then indeed, you, on the Day of Resurrection, before your Lord, will dispute" [Surah al-Zumar: 30 - 31], Sayyiduna Zubayr (may Allah be pleased with him) said: "O Messenger of Allah, will the matters that took place between us in the world be repeated, along with our particular sins?!" He (peace and blessings be upon him) said: "Yes, they will certainly be repeated before you until every one who has a right is given his right." Sayyiduna Zubayr (may Allah be pleased with him) said: By Allah, the matter is very severe indeed.
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both); he said: We lived a long period of our lives thinking that this verse, "Indeed, you are to die, and indeed, they are to die. Then indeed, you, on the Day of Resurrection, before your Lord, will dispute" [Surah al-Zumar: 30 - 31], was revealed only about us and the People of the Book. I used to say: Why would we dispute among ourselves?! We worship none but Allah, our religion is Islam, our Book is the Qur'an which we will never alter or distort, our qiblah is the Ka'bah, our sanctuary is one, and our Prophet is Muhammad (peace and blessings be upon him), so how could we dispute?! Until (in the era of trials) some of us struck the faces of others with swords; then I understood that this verse was indeed revealed about us.
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that Nafi' bin al-Azraq asked him about these sayings of Allah, the Mighty and Majestic: "This is a Day on which they will not speak" [Surah al-Mursalat: 35], "and you will hear nothing but a whisper" [Surah Ta Ha: 108], "and they will turn to one another, questioning each other" [Surah al-Saffat: 27], and "Here, read my record" [Surah al-Haqqah: 19]; so what is the reality of all these? He said: Woe to you, have you asked anyone other than me about this before? He said: No. He said: Beware! Had you asked (someone without knowledge), you might have been ruined. Has not Allah, the Mighty and Majestic, said: "And indeed, a day with your Lord is like a thousand years of those which you count" [Surah al-Hajj: 47]? He said: Yes. So he said: (The Day of Resurrection is very long, and) in each measure of these days there will be different states and different shades.
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.