創世記 1:10的米示拿參照：Mishnah Mikvaot, Mishnah Parah & Mishnah Negaim

All seas are equivalent to a mikveh, for it is said, "And the gathering (ulemikveh) of the waters He called the seas" (Genesis 1:10), the words of Rabbi Meir. Rabbi Judah says: only the Great Sea is equivalent to a mikveh, for it says "seas" only because there are in it many kinds of seas. Rabbi Yose says: all seas afford cleanness when running, and yet they are unfit for zavim and metzoraim and for the preparation of the hatat waters.

Flowing water is considered like a spring and dripping water is considered like a mikveh. Rabbi Zadok testified that if flowing water exceeded dripping water [with which it was mixed] it was valid [as flowing water]. If dripping water became flowing water, its flow may be blocked by a stick or by a reed or even by a zav or a zavah, and then one may go down and immerse oneself in it, the words of Rabbi Judah. Rabbi Yose says: one may not stop the flow of water with anything which is liable to uncleanness.

All seas are equivalent to a ritual bath (mikveh), for it is said, "And the gathering (ulemikveh) of the waters He called the seas" (Genesis 1:10), the words of Rabbi Meir. Rabbi Judah says: only the Great Sea is equivalent to a ritual bath, for it says "seas" only because there are in it many kinds of seas. Rabbi Yose says: all seas afford cleanness when running, and yet they are unfit for zavim and metzoraim and for the preparation of the hatat waters.