Mikvaot, Chapter One, Mishnah Two
This mishnah is basically the same exact mishnah as yesterday’s mishnah, except the water in the pool is defiled not by a person drinking directly from it but by a person filling up an unclean vessel from it.
1) If one drew water from it in an unclean vessel and then a clean person drank [out of the pit], he becomes unclean.
2) If one drew water [from it] in an unclean vessel and then drew water from it in a clean vessel, it becomes unclean.
3) If one drew water [from it] in an unclean vessel and a loaf of terumah fell in:
a) If he washed [his hands] in it, it becomes unclean;
b) But if he did not wash [his hands] in it, it is clean.