Sahih Bukhari
Ablutions (Wudu)
Volume: 001 / Book Number: 004 / Hadith Number: 144
Narrated Anas:
Whenever the Prophet went to answer the call of nature, he used to say, "Allah-umma inni a'udhu bika minal khubuthi wal khaba'ith i.e. O Allah, I seek Refuge with You from all offensive and wicked things (evil deeds and evil spirits)."