I always understood that a neder is forbidding physical pleasure or benefit from oneself. I believe this is the common understanding. However, I saw a surprising statement of the Maharal in his Tiferes Yisroel Chapter 6.
שאמרו במקומות הרבה 'מצות התורה לאו ליהנות נתנו', אלא בשביל גזירות נתנו...והטעם בכולם, מפני שמצות התורה לא נתנו ליהנות, רק לעול על האדם. ואל תאמר כי פירוש 'לאו ליהנות' בעולם הזה, רק לטוב לנו לעולם הבא. דאם היה תחלת נתינת המצוה לישראל להטיב להם בעולם הבא, אם כן מצות ליהנות נתנו.
They said in many places 'mitzvos were not given for pleasure/benefit'. Rather, they were given as decrees...the reason for all these instances is because the Torah wasn't given for pleasure, rather just as a yoke on a person. And don't tell me that 'not for pleasure/benefit' is meant for in this world, but [the Torah] was given for good in the next world. For if the whole point of giving the mitzvos to the Jews was for their benefit in the World to Come, then mitzvos were given for pleasure/benefit.
If I understood his words properly, he's saying that had the purpose of the Torah and mitzvos been to give us reward in the World to Come, that would be called הנאה, pleasure/benefit. If so, I would infer that a neder would be effective.
Consequently, I'm wondering if the natural consequence of this would be (according to him), that one could make a neder, forbidding oneself from benefitting from the reward in the World to Come? Is this is a correct conclusion? Does anyone discuss this possibility (with or without mentioning the Maharal). I do admit I'm not sure how this would play out practically.
In case someone wants to say the reward is לא בא לעולם, I would respond that according to the Nefesh HaChaim 1:12, the reward one creates with their mitzvos is בעולם, but we just don't have access to it yet.
