Sunan Abi Dawud 1522
سنن أبي داود#1522SahihMu'adh b. Jabal reported that the Messenger of Allah (ﷺ) caught his hand and said:By Allah, I love you, Mu'adh. I give some instruction to you. Never leave to recite this supplication after every (prescribed) prayer: "O Allah, help me in remembering You, in giving You thanks, and worshipping You well." Mu'adh willed this supplication to the narrator al-Sunabihi and al-Sunabihi to 'Abu Abd al-Rahman
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 ZaiIsnaad Sahih
In-book reference: 8:107