Sunan Abi Dawud 1460
سنن أبي داود#1460SahihUbayy b. Ka'b said:The Messenger of Allah (ﷺ) said: Abu al-Mundhir, which verse of Allah's Book that you have is creates ? I replied: Allah and His Apostle know best. He said: Abu al-Mundhir, which verse of Allah's that you have is greatest ? I said: Allah, there is no god but He, the Living, the Eternal. Thereupon he struck me on the beast and said: May knowledge be pleasant for you, Abu al-Mundhir
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 ArnautSahih
Zubair Ali ZaiSahih Muslim (810)
In-book reference: 8:45