Is there a Quranic verse, a noble Prophetic Hadith, or a saying of a Companion that supports the statement: "Indeed, your body has a right over you, and whoever abuses their youth will find their old age abused"? And is masturbation related to that?

The first phrase is part of a hadith agreed upon [by Al-Bukhari and Muslim]: "Indeed, your body has a right over you." The second phrase is a popular proverb whose meaning is attested by the hadith: "Guard Allah, and Allah will guard you." The meaning of Allah guarding His servant is that He guards their bodily health, strength, intellect, and wealth. Whoever guards their limbs in youth, Allah will guard them for them in old age. And whoever does not guard them, Allah may not guard them for them. Both phrases address masturbation due to its harms to the body, and whoever exhausts their body with masturbation in their youth will find the consequences of that in their old age, in addition to it being forbidden.