Surah Ikhlaas is equivalent to a Third of the Qur'an

Al-Bukhari recorded from Abu Sa`id that a man heard another man reciting
(Say: "He is Allah, One.'')
and he was repeating over and over. So when morning came, the man went to the Prophet and mentioned that to him, and it was as though he was belittling it.

The Prophet said,


(By He in Whose Hand is my soul, verily it is equivalent to a third of the Qur'an.)




Abu Dawud and An-Nasa'i also recorded it.

Another Hadith Al-Bukhari recorded from Abu Sa`id, may Allah be pleased with him, that the Messenger of Allah said to his Companions,

(Is one of you not able to recite a third of the Qur'an in a single night)



("Allah is the One, As-Samad'' is a third of the Qur'an.) Al-Bukhari was alone in recording this Hadith.

This was something that was difficult for them and they said, "Which of us is able to do that, O Messenger of Allah'' So he replied,



("Allah is the One, As-Samad'' is a third of the Qur'an.)


Al-Bukhari was alone in recording this Hadith.

End Quotes
Taken Tafsir Ibn Kathir
Surah Ikhlaas 
A Hadith that mentions this Surah is equivalent to a Third of the Qur'an