Narrated Abu Sa`id Al-Khudri:

A man heard another man reciting (in the prayers): 'Say (O Muhammad): "He is Allah, the One." (112.1) And he recited it repeatedly. When it was morning, he went to the Prophet (ﷺ) and informed him about that as if he considered that the recitation of that Sura by itself was not enough. Allah's Messenger (ﷺ) said, "By Him in Whose Hand my life is, it is equal to one-third of the Qur'an."

Narrated Abu Sa`id Al-Khudri:

A man heard another man reciting: Surat-ul-Ikhlas (The Unity) 'Say: He is Allah, the One (112) and he was repeating it. The next morning he came to Allah's Messenger (ﷺ) and mentioned the whole story to him as if he regarded the recitation of that Sura as insufficient On that, Allah's Messenger (ﷺ) said, "By Him in Whose Hand my soul is! That (Sura No. 112) equals one-third of the Qur'an."

Narrated Abu Said Al-Khudri:

A man heard another man reciting (Surat-Al-Ikhlas) 'Say He is Allah, (the) One.' (112. 1) repeatedly. The next morning he came to Allah's Messenger (ﷺ) and informed him about it as if he thought that it was not enough to recite. On that Allah's Messenger (ﷺ) said, "By Him in Whose Hand my life is, this Surah is equal to one-third of the Qur'an!"

Narrated Abu Said Al-Khudri: My brother, Qatada bin An-Nau'man said, "A man performed the night prayer late at night in the lifetime of the Prophet (ﷺ) and he read: 'Say: He is Allah, (the) One,' (112.1) and read nothing besides that. The next morning a man went to the Prophet (ﷺ) ,~ and told him about that . (The Prophet (ﷺ) replied the same as (in Hadith 532) above.)