What is the ruling on masturbation, and is there an authentic Hadith that indicates its prohibition?

Masturbation is forbidden, based on Allah's saying, when describing the believers: "And those who guard their private parts, except from their wives or those whom their right hands possess, for indeed, they will not be blamed - But whoever seeks beyond that, then those are the transgressors." And because the Prophet, peace and blessings be upon him, guided youth to marriage or fasting to manage their desires, and not masturbation, due to its harms to the body and mind. Its prohibition is derived from the noble verse, and there is no specific, authentic Hadith (definition) prohibiting it.