Niddah 4:1-2

Niddah 4:1

Samaritan women are considered niddahs from the cradle. Also, Samaritans render the bottom mattress ritually unclean just like the top mattress because they are intimate with niddahs and they count any color of blood as unclean (which messes up their calculations). However, one is not liable for entering the Temple wearing a Samaritan’s clothes, nor must one burn trumah if such clothes touch it, because their ritual impurity is a case of doubt.

Niddah 4:2

Sadducee women are considered like Samaritan women so long as they persist in the practices of their ancestors. If they cease such practices and follow the Jewish way, then they’re like all other Jews. Rabbi Yosi says that Sadducee women are always considered like Jewish women unless they cease following the Jewish way and start following the practices of their ancestors.