The Prophet ﷺ, whenever he entered the lavatory, would say, "O Allah, I seek refuge in You from male and female devils."
أخبرنا أحمد بن عبدة الضبي البصري حدثنا حماد بن زيد عن عبد العزيز بن صهيب
أن النبي ﷺ كان إذا دخل الخلاء قال اللهم إني أعوذ بك من الخبث والخبائث
Agreed upon by Muslim and Bukhari. Muslim, Hayd, chapter of what one says when intending to enter the toilet, no. 375, from the hadith of Hammad bin Zayd, and Bukhari, Wudu, chapter of what one says at the toilet, no. 142, from the hadith of Abdul-Aziz bin Suhayb, through him.