Abu Sa`id Al-Khudri (Radhiallahu anhu) reported about Surat Al-Ikhlas (Chapter 112):
The Messenger of Allah (Sallallaahu 'alaihi wasallam) said, "By Him in Whose Hand my soul is, it is equivalent to one-third of the Qur'an.''
According to another version, he (Sallallaahu 'alaihi wasallam) said to his companions:
"Is anyone of you incapable of reciting one-third of the Qur'an in one night?''
They considered it burdensome and said: "O Messenger of Allah, which of us can afford to do that?''
He (Sallallaahu 'alaihi wasallam) said, "Surat Al-Ikhlas [Say: He is Allah (the) One] is equivalent to one-third of the Qur'an.''
[Al-Bukhari]
The Messenger of Allah (Sallallaahu 'alaihi wasallam) said, "By Him in Whose Hand my soul is, it is equivalent to one-third of the Qur'an.''
According to another version, he (Sallallaahu 'alaihi wasallam) said to his companions:
"Is anyone of you incapable of reciting one-third of the Qur'an in one night?''
They considered it burdensome and said: "O Messenger of Allah, which of us can afford to do that?''
He (Sallallaahu 'alaihi wasallam) said, "Surat Al-Ikhlas [Say: He is Allah (the) One] is equivalent to one-third of the Qur'an.''
[Al-Bukhari]