Mikvaos 1:5-6

Mikvaos 1:5

Beis Shammai say that pool water is considered ritually clean when rainwater exceeds its volume to the point that it overflows; Beis Hillel say when rainwater exceeds its volume even if it doesn’t overflow. Rabbi Shimon says when rainwater makes it overflow even if it doesn’t exceed its volume. Such water is valid for preparing dough from which challah will be taken and for the ritual washing of hands.

Mikvaos 1:6

Higher than pool water and comparable mikvaos (see mishna 1:4) are rainwater ponds whose flows have not stopped. If a ritually-unclean person drank from it and then a ritually-clean person drank from it, he remains clean. If a ritually-unclean person drank from it and then water was drawn from it using a ritually-clean utensil, it remains clean. If a ritually-unclean person drank from it and then a loaf of trumah fell into the pool, it remains clean even if he rinsed the loaf in it. If someone drew water from the pool using an unclean utensil and then a ritually-clean person drank from the pool, he remains clean. If someone drew water from the pool using an unclean utensil and then someone drew water from the pool using a ritually-clean utensil, it remains clean. If someone drew water from the pool using an unclean utensil and then a loaf of trumah fell in, it remains clean even if he rinsed the loaf in it. If unclean water fell into the pool and a ritually-clean person drank from it, he remains clean. If unclean water fell into the pool and someone drew water from it using a clean utensil, it remains clean. If unclean water fell into the pool and then a loaf of teumah fell in, it remains clean even if he rinsed the loaf in it. Such water is fit for trumah and for the ritual washing of hands.