Jami' at-Tirmidhi 3606

“Abu Bakr said: ‘O Messenger of Allah, command me with something that I may say when I reach morning and evening.’ He said: ‘Say: “O Allah Knower of the Unseen and the Seen, Originator of the heavens and the earth, Lord of everything and its Possessor, I bear witness that there is none worthy of worship except You, I seek refuge from You from the evil of my soul and from the evil of Shaitan and his Shirk (Allāhumma `ālimal-ghaibi wash-shahādati fāṭiras-samāwāti wal-arḍ, rabba kulli shai’in wa malīkahu, ash-hadu an lā ilāha illā anta, a`ūdhu bika min sharri nafsī wa min sharrish-shaiṭāni washirkihi).’” He said: ‘Say it when you reach morning, and evening, and when you go to bed.’”