Musnad Ahmad 1018:22

Waki’ narrated to us, Sufyan narrated to us, from Suhayl ibn Abi Salih, from his father, from a man from Aslam, who said: The Prophet (peace and blessings of Allah be upon him) said to a man: "If you were to say when you enter the evening: 'I seek refuge in the perfect words of Allah, all of them, from the evil of what He created,' no scorpion would harm you until you reach the morning."