2,107. Blood Stains on Objects That Are Insusceptible to Impurity
Hilchos Issurei Biah 9:7
If a blood stain is found on something that is insusceptible to ritual impurity, the woman remains ritually clean and she need not be concerned about it. For example, let’s say that a woman sat on a utensil of stone, earth, dung or fish skin, on the outside of an earthenware utensil or on a cloth that is smaller than three fingerbreadths square. If blood was found on that item, she remains ritually clean. This is so even if the woman inspected the ground, sat on it and found a blood stain upon arising. She remains ritually clean because the Sages didn’t enact that a woman should be rendered unclean when a stain is found on something that’s insusceptible to ritual impurity. Furthermore, they only enacted that she is unclean when the object on which the stain is found is white; when an object is colored, we are not concerned when a stain is found on it. Because of this, the Sages enacted that a woman should wear colored garments in order to protect herself from the issues raised by finding blood stains.
Hilchos Issurei Biah 9:8
A woman isn’t rendered ritually unclean because of a blood stain found anywhere on her body; it must be found opposite the genitals. Accordingly, if a stain is found on her heel, she is rendered unclean because her heel may have touched her genitals while sitting cross-legged. She is likewise rendered unclean if a stain is found on her calf or on the inner side of her ankle, as these will touch when she stands with her feet and calves together. If the blood stain is found on the end of her toe, she is rendered unclean because uterine blood might have dripped onto her foot when she walked. Similarly, if blood is found in anywhere that menstrual blood might have splattered while walking, she is rendered ritually unclean. If blood is found on her hands – even on the backs of her fingers – she is ritually unclean because one’s hands are always touching things. However, if blood is found on the outside or the side of her calf – and certainly if it’s found from her thigh and up – then she remains she ritually clean because this is surely blood that splashed onto her from someplace else.