Hazrat Jabir Bin Abdullah (RA) narrates that once Prophet Muhammad (PBUH) and he along with a group of other mahajarin were in a house and this group of mahajarin included Hazrat Abubakar, Hazrat Umar, Hazrat Usman ,Hazrat Ali, Hazrat Talha, Hazrat Zubair, Hazrat Abdur-Rahman bin Auf, and Hazrat Saad bin Abi Waqas. Prophet Muhammad (PBUH) then instructed everyone to pair up with one another and Prophet Muhammad (PBUH) himself paired up with Hazrat Usman(RA) saying that, O Usman(RA)! You are my friend in this world and hereafter. (Imam Haakim, Imam Abu Yali)
Hazrat Jabir bin Abdullah(RA) narrates that Prophet Muhammad(RA) and he went to a female companion’s house and she slaughtered a goat in their honour. It was then that Prophet Muhammad (PBUH) said that now a resident of paradise will enter and after some time Hazrat Abu Bakar Siddiq(RA) entered, then Prophet Muhammad(PBUH) said that another resident of the jannah will now enter and after some time Hazrat Umar(RA) entered. Prophet Muhammad (PBUH) again said that another resident of the jannah will enter now and he also prayed that Allah, if you are willing then let that person be Ali. The narrator told that the next person who entered was Hazrat Ali (RA).(Imam Ahmad, Imam Haakim, also Imam Haakim said that this hadith is Sahih-al-Asnaad.)
Hazrat Bara ibn Azib(RA) narrates that Prophet Muhammad(PBUH)looked at رضوان اللہ اجمعین Hazrat Hussain and Hazrat Hassan and prayed that Allah, I love these two, u too love them. (Imam Tirmizi).
Hazrat Abdullah bin Masood(RA) narrates that Prophet Muhammad (PBUH) said that for he who loves me it is necessary that he also loves Hazrat Hassan and Hazrat Hussain رضوان اللہ اجمعین (Imam Nisai, Ibn-e-Khazima)
