Muhammad bin Abi 'Adi محمد بن أبي عدي · The Book of Seeking Refuge with Allah

"I said: 'O Messenger of Allah, teach me a supplication from which I may benefit.' He said: 'Say: Allahumma 'afini min sharri sam'i, wa basari, wa lisani, wa qalbi, wa min sharri mani (O Allah, protect me from the evil of my hearing, my seeing, my tongue and my heart, and from the evil of my sperm.)'" - Meaning sexual organ.

The Prophet used to seek refuge from being destined to an evil end, from his enemies rejoicing in his misfortune, from being overtaken by destruction and from the difficult moment of a calamity.