Who said "A man is his own most dangerous opponent."?

This quote is attributed to Sophocles.

A man is his own most dangerous opponent. - Sophocles

"A man is his own most dangerous opponent."

Sophocles Strength

Tragic Playwright Ancient Greece 496–406

"Wisdom brings suffering to those who possess it."

"Nobody likes the man who brings bad news."

"All that is and will be comes forth from necessity."

"To the man who is afraid everything rustles."

"Strength comes from within."

"A woman should be proud of who she is."

"A strong woman can overcome anything."

"The only thing I'm good at is killing."