How is there a distinction between the two (unmarried and married)? An unmarried man needs to immerse if he had a nocturnal emission, but a married man does not?

With God’s help,
translation: when Rabbi Yehoshua ben Levi says, “A seminal emission is only marital relations,” he is basically saying that a nighttime emission from a dream is not considered a seminal emission. That means a married man has his wife, but an unmarried man does not, and since Ezra the Scribe did not distinguish between the two, only emission by hand remains. And this requires re-examining the concept of “wasting seed.”

The question is sloppily worded, and I should really have deleted it entirely. Even so, I’ll try to answer if I understood correctly. First, it’s possible that “relations” also includes emitting semen in general (that is, anything active, as opposed to a nocturnal emission). Second, I don’t understand why you assume there is no distinction between an unmarried and a married man. And third, it’s not clear what exactly your question is regarding wasting seed.
If you continue not to be clear, I’ll delete the whole thread.

With God’s help,
okay, so I’m asking the opposite question: if so, why didn’t Ezra the Scribe excommunicate a person who emitted semen by hand? The earliest explicit source about wasting seed in connection with excommunication is the statement, “One who deliberately stimulates himself should be under excommunication.” Why don’t we find any of the prophets saying this? Why don’t we find in earlier traditions some great authority who would excommunicate a person who wasted seed? If this is a matter of heavenly excommunication, like the case of Er and Onan, that can be understood, but why did no authority ever actually excommunicate someone for wasting seed?

There is also a practical difference among those who disagree about the very nature of the prohibition, whether it is rabbinic or Torah-level. If it is Torah-level, there is no choice; if it is rabbinic, there is choice. Is the prohibition one of deriving benefit? What are its reasons? Why does the Beit Yosef, based on a responsum of the Chida, permit female masturbation? There are also scientific reasons that would exempt males from the prohibition just as much as females.

The Rabbi can delete the thread; I’ve already understood the answer, and I’ve already understood that there’s no one to talk to. ChatGPT understood the meaning of the question: since no distinction exists in the sages’ ordinance, what relevance is there to Ezra instituting immersion for unmarried men? Since when is it relevant for an unmarried man to emit semen except in a nocturnal emission? But Rabbi Yehoshua ben Levi also rules that out. Rabbi Avraham Rubin also told me that yes, Ezra instituted it because of nocturnal emission. So according to Rabbi Yehoshua ben Levi it is clear that wasting seed does not apply to every emission as such.

With God’s help, it is also written in the Jerusalem Talmud that one of the reasons Ezra the Scribe instituted immersion was because of sinners who are God-fearing, like the example of that man who propositioned a woman for a sinful matter and she said to him, “Empty one, do you have forty se’ah?” and he left her! Just a second: so why was Ezra’s ordinance of immersion abolished? Even today there are God-fearing people, and this would prevent them from emitting semen in vain by hand, because they would refrain from what would forbid them to study Torah without immersion, according to these ideas. Rather, the implication is that the whole prohibition is from the standpoint of the transgression and not from the standpoint of the emission itself, whether by hand, by thought, or through one’s wife. Because the prohibitions of needless destruction and “do not stray after” apply regardless of how the emission happens. But yes, may the Messiah come soon, God willing, and everything will become clear on this.