Sunan Abi Dawud 4008
سنن أبي داود#4008SahihNarrated 'Aishah: The revelation came down to Messenger of Allah (ﷺ) and he recited to is: "A surah which We have sent down and which We have ordained (faradnaha)" Abu Dawud said: The letter ra (r) is the word faradnaha has short vowel a (with out doubling of consonant r), and then he reached the verses after this verse
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih Isnaad
Muhammad Muhyi Al-Din Abdul HamidSahih Isnaad
Zubair Ali ZaiIsnaad Sahih
In-book reference: 32:40