Book
Mikvaot מקוואות
a tractate of the order of Tohorot
Purification comes only by immersion, and only in water that gathered naturally: rain, a spring, melted snow. Drawn water does not make a mikveh. The tractate works through the grades of pools, the required measure, the joining of two waters and everything that can obstruct immersion.
A subject of its own is "chatzitzah": anything stuck to the body that separates it from the water invalidates the immersion, and a person must enter the water wholly, with nothing between. Today's mikveh and all the rules for immersing vessels rest on these laws.
Order: Tohorot. There is no Gemara in either Talmud—the tractate remained mishnah.
On the timeline
Related
Sources
Chazal: Mishnah, Talmud, midrash, Zohar
- Leviticus 11:36 — «a spring or a cistern, a gathering of water»
- Mishnah Mikvaot 1:1 — the grades of water sources
Basis: Talmud and midrash.