From Sahih Muslim (Hadith 1912):
Shaqiq reported:A person from Banu Bajila who was called Nabik b. Sinan came to Abdullah and said: I recite mufassal surahs in one rak'ah. Upon this 'Abdullah said: (You recite) like the recitation of poetry. I know the manner in which the Messenger of Allah (ﷺ) recited two surahs in one rak'ah
Reference: Muslim 1912