The second perek of Massekhet Nidda, which begins on today’s daf discusses the need for a woman to examine herself to establish her status regarding ritual purity in order to know whether she can eat teruma and sanctified foods or engage in sexual relations with her husband. The Torah teaches that a woman who experiences a flow of menstrual blood becomes ritually unclean (see 15:19), so it is logical that she should examine herself to ascertain whether she has become a nidda.
What is the status of a woman who is unable to examine herself? How can she be deemed ritually pure?
The Mishna on today’s daf teaches –
In the case of a woman who is deaf, or an imbecile, or blind or who went insane, if she has competent friends they examine her and prepare her to then partake of teruma.
The Gemara attempts to clarify each of the cases of the Mishna. Regarding a ḥereshet – the deaf woman – the Gemara asks why there is a need to have others assist her. To support this question a baraita is brought in which Rabbi Yehuda HaNasi relates that a deaf woman in his community was an expert in the laws on nidda, and, in fact, the other women turned to her to examine their blood to determine whether or not it was menstrual blood. In response the Gemara distinguishes between a woman who cannot hear but has the ability to speak and a deaf-mute who is viewed by the Gemara as incompetent, saying
“The deaf person of whom the Sages spoke is always one who can neither hear nor speak.”
At the beginning of Massekhet Ḥagiga we find different explanations that have been offered to explain this position of the Sages. According to Rashi, the Sages simply had an oral tradition that a deaf-mute is not halakhically competent, even if they do not display the signs of an imbecile. The Talmud Yerushalmi, however, rules that the principles such as this one that are found in the Mishna often times have exceptions, as is the case here. Depending on the circumstances, a ḥeresh may be considered intelligent, even if listed together with an imbecile and minor who are viewed as incompetent.