What is the ruling on masturbation in a situation where one is unable to marry and seeks to avoid fornication?

Masturbation is absolutely forbidden. Whoever cannot afford to marry must practice abstinence, as Allah Almighty commanded in Surat An-Nur: "And let those who find not [the means for] marriage abstain [from sexual relations] until Allah enriches them from His bounty." The Prophet (peace be upon him) guided youth to marry if they are able, and for those who are not able, then they should fast, for it will be a shield for them.