It was narrated that Ibn 'Abbas said:
"The Messenger of Allah said: 'One Faqih (knowledgeable man) is more formidable against the Shaitan than one thousand devoted worshippers.'" (DE)
English reference (DE): Vol. 1, Book 1, Hadith 222 (DE)
Arabic reference (DE): Book 1, Hadith 227 (DE)