How sound is the Hadith: "May Allah curse him who marries his hand"? And is masturbation more merciful than fornication and sodomy?

The aforementioned Hadith, "Cursed is he who marries his hand," is not authentically reported from the Messenger of Allah, peace and blessings be upon him. Al-Ajlouni, Ali al-Qari, and others have explicitly stated this. Other wordings of the Hadith have also been reported, such as: "Seven types of people Allah will not look at... and he who marries his hand," but these are also weak.

Although masturbation is forbidden, based on Allah's saying: (And those who guard their private parts. Except from their wives or those their right hands possess, for indeed, they are not to be blamed. But whoever seeks beyond that, then those are the transgressors), it is lesser in severity than adultery and sodomy. One must abstain from it.