Parah 8:7 - 8:8

כל הפוסל את התרומה – as for example hands which are second-degree [of impurity], make liquids first-degree to defile non-holy things, but hands themselves that came in contact with non-holy foodstuffs, are pure, for something that is second-degree [in defilement] does not make non-holy things third-degree [uncleanness].

חוץ מטבול יום - whose sunset had not yet arrived. Even though he defiles the heave offering, he does not defile liquids to become first-degree [uncleanness], and even the liquids of heave-offering if a person who had immersed himself that day had come in contact with them, other than those things which are invalid alone are not ritually impure (see also Tractate Kelim, Chapter 8, Mishnah 4).

כל הימים כמקוה – for all of these words as it is taught at the conclusion [of this Mishnah]. (And also) they do not render clean when running like springs, for a Mikveh does not purify in running/moving waters, but rather in collected waters, as is written (Leviticus 11:36): “However, a spring/אך מעין [or cistern in which water is collected shall be pure,]” a spring purifies in moving/running waters but a Mikveh does not purify in moving/running waters.

ופסולין לזבין – for a man with gonorrhea/flux requires living waters, as it is written (Leviticus 14:9): “and bath his body in water; [then he shall be pure].” (see also Leviticus 16:26 and 16:28), and for the leper [as it is written (Leviticus 14:5): “[The priest shall order one of the birds slaughtered over] fresh water in an earthen vessel/אל-כלי-חרש על-מים חיים” [and for the waters of the sin offering], as it is written (Numbers 19:1): “and fresh water shall be added to them in a vessel.”

הים הגדול כמקוה – Scripture did not call a Mikveh other than the Great Ocean, for in it Scripture refers in the Creation Story for there all the waters of Creation were gathered, and it doesn’t state “seas”/ימים – in the plural, other than because many seas are mixed in together in it, for all the streams travel to it.

ר' יוסי אומר – all the seas and the Great Ocean have the status of a spring upon them regarding the fact that they purify in moving/running waters, because the streams go and flow upon them. But they are invalid regarding the status of living waters, for Scripture calls them Mikveh. And the Halakha is according to Rabbi Yossi.