If abstaining from doubtful matters is commendable, then is masturbation considered a doubtful matter and is its ruling commendable?

The fatwa states that avoiding doubtful matters is recommended according to the preponderant opinion. No one has said that engaging in doubtful matters is recommended. Rather, they differed regarding the ruling on avoiding them: some said it is forbidden, some said it is disliked, and some refrained from giving a definitive ruling. As for masturbation, it is forbidden and must be avoided.