'Abdullah bin Muhammad narrated the same hadith on the authority of Abu Hurairah (RA) and in the transmission by Malik the words are that he (the Holy Prophet) recited the verse:" but that my heart may rest at ease" and completed it.
Hadith Referenceصحيح مسلم / كتاب الإيمان / 151
Hadith Gradingمحدثین:أحاديث صحيح مسلم كلها صحيحة
Hadith Takhrij«أحاديث صحيح مسلم كلها صحيحة ، تقدم تخريجه برقم (381)»
Abu Hurairah (RA) reported: The Messenger of Allah (ﷺ) said: He who said his prayer, but did not recite the opening chapter of al-Kitab, his prayer is incomplete. He repeated it thrice.