I came to the Prophet ﷺ and said, "Prophet of Allah, teach me a prayer of refuge that I may use to seek protection."He took my hand and said, "Say, I seek refuge in You from the evil of my hearing, the evil of my sight, the evil of my tongue, the evil of my heart, and the evil of my semen."He kept repeating it until I memorized it.Saad explained that "al-mani" refers to a man's fluid.
أخبرنا الحسن بن إسحق قال حدثنا أبو نعيم قال حدثنا سعد بن أوس قال حدثني بلال بن يحيى أن شتير بن شكل أخبره
أتيت النبي ﷺ فقلت يا نبي الله علمني تعوذا أتعوذ به فأخذ بيدي ثم قال قل أعوذ بك من شر سمعي وشر بصري وشر لساني وشر قلبي وشر منيي قال حتى حفظتها قال سعد والمني ماؤه
[Its chain is hasan] Abu Dawud narrated it in the Book of Prayer, chapter on seeking refuge, no. 1551, from the hadith of Saad bin Aws. Tirmidhi narrated it, no. 3492, and said, hasan gharib, and it is also in Kubra, no. 7877. Hakim graded it sahih, 1/532-533, and Dhahabi agreed with him.