These ten Companions of the Prophet (s) are called the ‘ashra mubashshara'. Although there are some minor variations in the Islamic sources, here is one narration that identifies those 10 individuals.

The Messenger of Allah said: "Abu Bakr is in Paradise, ‘Umar is in Paradise, ‘Uthman is in Paradise, ‘Ali is in Paradise, Talhah is in Paradise, al-Zubayr is in Paradise, ‘Abd al-Rahman b. ‘Awf is in Paradise, Sa’d b. Abi Waqqas is in Paradise, Sa’id b. Zayd is in Paradise, and Abu ‘Ubaydah b. al-Jarrah is in Paradise."

So here are some interesting facts about this narration:

1. The first four people in the list became caliphs in exactly that order. Each of them became caliph in a different way. Abu Bakr in a heated exchange in the hall of Saqifa, ‘Umar as appointed by Abu Bakr on his deathbed, ‘Uthman as a result of the odd committee handpicked by ‘Umar with the express purpose of preventing ‘Ali from becoming the next caliph. And ‘Ali in a popular election after the violent riots against ‘Uthman caused his murder.
    
2. None of the caliphs, or any of their supporters, ever quoted this narration to justify their eligibility for the caliphate.
    
3. All of the people listed are Muhajir, none of them Ansar.
    
4. According to a well-known hadith in Sahih al-Bukhari Fatima, the daughter of the Prophet Muhammad (s), was angry with Abu Bakr and stopped speaking to him, and continued assuming that attitude till she died. She is considered by consensus of all Muslims to be the leader of all Muslim women in paradise.
    
5. ‘Umar got informed once that people were planning on giving the oath of allegiance to ‘Ali after his death. He addressed the people and said:

   (O people!) I have been informed that a speaker amongst you says, 'By Allah, if `Umar should die, I will give the pledge of allegiance to such-and-such person.' 

   One should not deceive oneself by saying that the pledge of allegiance given to Abu Bakr was given suddenly and it was successful. No doubt, it was like that, but Allah saved (the people) from its evil, and there is none among you who has the qualities of Abu Bakr. 

   Remember that whoever gives the pledge of allegiance to anybody among you without consulting the other Muslims, neither that person, nor the person to whom the pledge of allegiance was given, are to be supported, lest they both should be killed. 

   And no doubt after the death of the Prophet (s) we were informed that the Ansar disagreed with us and gathered in the shed of Bani Sa’ida. ‘Ali and Zubayr and whoever was with them, opposed us, while the emigrants gathered with Abu Bakr. 

   I said to Abu Bakr, 'Let's go to these Ansari brothers of ours.' So we set out seeking them, and when we approached them, two pious men of theirs met us and informed us of the final decision of the Ansar, and said, 'O group of Muhajirin (emigrants) ! Where are you going?' 

   We replied, 'We are going to these Ansari brothers of ours.' They said to us, 'You shouldn't go near them. Carry out whatever we have already decided.' I said, 'By Allah, we will go to them.' And so we proceeded until we reached them at the shed of Bani Sa’ida… Full narration from Sahih al-Bukhari linked here
    

6. ‘Uthman was not open to good advice from ‘Ali suggesting he fix financial malpractices in his government filled with his Umayyad relatives.

   Narrated by Ibn Al-Hanafiya: If Ali had spoken anything bad about 'Uthman then he would have mentioned the day when some persons came to him and complained about the Zakat officials of 'Uthman. 

   'Ali then said to me, "Go to 'Uthman and say to him, 'This document contains the regulations of spending the Sadaqa of Allah's Apostle so order your Zakat officials to act accordingly." 

   I took the document to 'Uthman. 'Uthman said, "Take it away, for we are not in need of it."

   Source: Sahih al-Bukhari, Volume 4, Book 53, Number 343
    

7. Abu ‘Ubaydah b. al-Jarrah was the one who went with Abu Bakr and ‘Umar to Saqifa, hours after the Prophet (s) died, to ensure the Ansar did not take over the caliphate. He was presented as a candidate for caliphate in that meeting by Abu Bakr.
    
8. Talha came out in open warfare against ‘Ali in the Battle of Jamal. In that conflict he sent word to Talha b. ‘Ubaydullah to come and meet him. Talha came to him and ‘Ali said:

   “I adjure you by Allah, did you hear the Messenger of Allah say: "Of whomsoever I am master, `Ali is his master. O Allah, befriend the one who befriends him and be at enmity with one who is at enmity with him?"

   He said: "Yes." ‘Ali said: "Then why do you fight against me?"

   He said: "I do not remember." He (the narrator) said: Then Talha departed.

   Source: al-Hakim al-Naysaburi, al-Mustadrak `ala al-Sahihayn, Haydarabad: Da'irat al-ma`arif al-nizamiyyah (4 vols), 1334-42 AH vol. 3, p. 371
    

9. Sa’d b. Abi Waqqas did not participate in any battles alongside ‘Ali during his rule. He preferred to stay neutral.
    
10. That leaves Sa'id b. Zayd. Other than the fact that he also did not participate in Jamal or Siffin alongside 'Ali, this brother-in-law of 'Umar b. al-Khattab also has one more remarkable attribute.

    He is the only one to narrate this hadith that includes himself in the list!

CONCLUSION

The narration of the 10 who were promised paradise is simply fake news! It is yet another example of fabricated narrations created during and after the civil wars to bolster a Sunni narrative that aimed to cover over the cracks left from that period of great fitna and division in the Muslim community.