Abdullah ibn Haarith radiyallahu anhu reports, “I did not see anyone who smiled more than Rasoolullah sallallahu alaihe wasallam.”

Abdullah ibn Haarith radiyallahu anhu relates, “The laugh of Sayyidina Rasoolullah sallallahu alaihe wasallam was but a smile.”

Abu Dhar radiyallahu anhu says, “Rasoolullah sallallahu alaihe wasallam said, “I know that person well who will enter Jannah first and also that person who will be the last one to be taken out of Jahannam. On the Day of Qiyaamah a person will be brought forward to the court of Almighty Allah. It shall be commanded that all the minor sins of that person be put forward to him and the major sisn be concealed. When the minor sins are disclosed to that person, he will
accept that he had committed them, as there will be no room for refuting them. (He will begin to tremble and say in his heart that these are only the minor sins, what will happen when the major sins are exposed.) During this happening it shall be commanded that for every sin of that person he be given the ajr (thawaab-reward) of a good deed. Upon hearing this person himself will say I
still have many sins left to account for, that are not seen here.” Abu Dhar radiyallahu anhu says, “Rasoolullah sallallahu alaihe wasallam while narrating the words of that person began laughing until his mubarak teeth began to show.” (The reason being that the person himself disclosed the very sins he was frightened of.)

Jabir ibn Abdullah radiyallahu anhu says, “After I accepted Islam, Rasoolullah sallallahu alaihe wasallam never prohibited me from attending his assemblies. Whenever he saw me he laughed.” In the second narration it is stated that he smiled.

Abdullah ibn Mas’ood radiyallahu anhu said, “I know the person who will come out last from the fire. He will be such a man who will crawl out (due to the severity of the punishment of Jahannam he will not be able to walk). He will then be ordered to enter Jannah. He will go there and find that all the places therein are occupied. He will return and say, ‘O Allah the people have
taken all the places.’ It will be said to him. ‘Do you remember the places in the world?’ (That when a place gets filled, there remains no place for a newcomer. And a person that arrives first occupies as much as one pleases, there remains no place for the ones that arrive later. The elders have translated it in this manner. According to this humble servant, if the meaning of it is taken as follows, it seeems more appropriate, that do you remember the vastness and plentiness of the world and how big the world was. He is being reminded, because an announcement is going to be made that a place that is ten times greater than the world shall be given to him. After
imagining the vastness of the world once, it may be assesed how great this gift is?). He will reply, ‘O my creator, I remember well.’ It will be commanded to him. ‘Make your wish in whichever way your heart desires.’ He will put forward his desires. It shall be commanded. All your desires are fulfilled and in addition ten times the size of the world is granted to you. He will
reply, ‘Are you jesting with me O my Allah, and You are the King of the Kings? (There is no place in Jannah and You are granting me a place ten times greater than the world).” Sayyidina Ibn Mas’ood radiyallahu anhu said, “I saw Rasoolullah sallallahu alaihe wasallam laugh till his mubarak teeth showed, when he related this portion of the man’s reply.

Ali ibn Rabiah radiyallahu anhu says, “I was present when a conveyance (A horse or something) was brought to Hazrat Ali radiyallahu anhu (in the period of his khilafah). He recited Bismillah and put his leg in the stirrup. After he had mounted he said Alhamdulillah and recited this dua:

Translation: Glorified be He Who hath sudued those unto us, and we were not capable (Of subduing them); And lo! Unto our Lord we are returning. (Surah Zukhruf 13-14)

Ali radiyallahu anhu then said Alhamdulillah three times, Allahu Akbar three times, then recited:
Translation: Glorified be Thou! Behold, I have wronged myself. So forgive thou me. Indeed, non forgiveth sins but Thou.

Then (Sayyidina Ali radiyallahu anhu) laughed (smiled). I said to him, ‘What is the reason for laughing, O Ameerul Mumineen?’ He replied, ‘Rasoolullah sallallahu alaihe wasallam also recited these duas in this manner and thereafter laughed (smiled). I also inquired from Rasoolullah sallallahu alaihe wasallam the reason for laughing (smiling) as you have asked me.
Rasoolullah sallallahu alaihe wasallam said, ‘Allah Ta’ala becomes happy when His servants say, ‘No one can forgive me save You.’ My servant knows that no one forgives sins besides Me.