After a transitive verb comes the word את, not the prefix letter מ. And when it is written החתים בשרו מזובו (his flesh be stopped from his issue)⁶⁷, there is a homiletical interpretation.

Aפועל יוצא*(transitive verb) is a verb that acts on an object. An intransitive verb is a verb that does not act on an object.*

When Leviticus 15:3 says,וזאת תהיה טמאתו בזובו רר בשרו את זובו או החתים בשרו מזובו טמאתו הוא(And this shall be his uncleanness in his issue: whether his flesh run with his issue, or his flesh be stopped from his issue, it is his uncleanness), it uses the prefix letterמbefore “his issue” inהחתים בשרו מזובו (his flesh be stopped from his issue) instead of the wordאת*, contradicting Rule 33. The homiletical interpretation is thatבשרו(his flesh) is the subject and reason for it being stopped from his issue, and nothing else⁶⁸.*

footnotes: ⁶⁷ Leviticus 15:3. ⁶⁸ Malbim, HaTorah v’HaMitzvah Metzora 122.