Sunan Abi Dawud 1523
سنن أبي داود#1523SahihNarrated Uqbah ibn Amir: The Messenger of Allah (ﷺ) commanded me to recite Mu'awwidhatan (the last two surahs of the Qur'an) after every prayer
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautHasan
Zubair Ali ZaiIsnaad Hasan
In-book reference: 8:108