According to the Hadith, Surat-ul-lkhlaas is (equivalent to) a third of the Quran. And according to one 1-hadeeth its reward is equal to a third of the Quran.
Regarding a certain Sahabi who was an lmaam and he used to mostly recite Qul Huw Allahu Ahad,Prophet Muhammed said "Tell him that Allah loves him".
It is mentioned in one Hadith that a Sahabi always used to recite Suratul Ikhlaas together with other Surahs in every rak'ah he used to perform. On being asked the reason, he replied that he loved this Surah very much. Upon this Prophet Muhammed said "The love for this Surah will admit you into Jannah."
According to a Hadith when Prophet Muhammed heard a Sahabi reciting this Surat-ul-ikhlas with full sincerity,he said: "Jannah is a must for this person."
According to a hadith Prophet Muhammed said " swear by the One in whose hands lie my life that Surah lkhlaas is equivalent to a third of the Qur'aan."
According to a Hadith Prophet Muhammed said: "Anyone who lies down on the bed with intent to sleep, and while lying on his right side recites Qul Huw Allahu Ahad a hundred times, then on the Day of Qiyaamah, The Sustainer will say: "My servant, proceed into Jannah on your right side."