Sunan Abi Dawud 3980
سنن أبي داود#3980SahihNarrated Ubayy b. Ka'b:"Say, in the bounty of Allah, and in His mercy- in that let you rejoice
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniHasan Sahih
Muhammad Muhyi Al-Din Abdul HamidHasan Sahih
Shuaib Al ArnautHasan
Zubair Ali ZaiHasan
In-book reference: 32:12