Signs for Differentiating Between Blood of Hayd and Istihadah

“Once a woman came to abu ’Abd Allah (a.s.), and asked about the case of a woman who experiences blood discharge which does not stop and she does not know whether it is Hayd (menses) or something else. He (the narrator) has said that he (the Imam) then said, ‘Blood discharged because of Hayd (menses) is hot, thick and of black color. It comes with pressure and hotness. Blood discharge because of Istihadah (irregular menses) is of yellow color and cold. If blood discharged is hot, comes with pressure and it is of black color, she must stop performing Salah (prayer).’ He (the narrator) said that she left saying, ‘By Allah, were it a woman she could not explain it any better than what he (the Imam) did.’”

“Abu ‘Abd Allah (a.s.), has said, ‘Blood discharge because of Istihadah (irregular menses) and Hayd (menses) does not come from the same place. Blood discharge because of Istihadah (irregular menses) is cold, and because of Hayd (menses) it is hot.’”

A woman from among us asked me to bring her to Abu Abdillah (as), so I sought permission for her, and he granted it. She entered, accompanied by her servant. She said to him, “O Abu Abdillah, regarding the verse ‘a blessed olive tree, neither of the east nor of the west’ (24:35), what does this mean?” He said to her, “O woman, Allah did not give examples of the tree for its own sake, but rather gave examples for the children of Adam. Ask what you mean.”
She then asked, “Tell me about women who engage in immoral acts with other women—what is their punishment?” He said, “The punishment for such acts is the same as for zina (fornication). On the Day of Judgment, they will be brought forth, clothed in garments of fire, struck with iron rods of fire, and covered in fire. From their innards to their heads, pillars of fire will be placed, and they will be cast into the Hellfire. O woman, the first people to commit such an act were the people of Lot. When men turned away from women and sought satisfaction with men, the women were left without men, so they did as their men had done, seeking satisfaction with one another.”
She then said to him, “May Allah bless you, what do you say about a woman who has her period, and her days of menstruation pass?” He replied, “If her menstruation lasts less than ten days, she should wait an additional day to be certain, and after that, she is considered to be experiencing istihadha (irregular bleeding).”
She then asked, “What if her bleeding continues for a month, two months, or three months—what should she do about her prayers?” He replied, “She should sit out the days of her menstruation, then she should perform ghusl for each two prayers.”
She further asked, “What if her menstruation varies, sometimes coming a day or two or three earlier or later—how would she know?” He said, “The blood of menstruation is not hidden; it is hot and causes a burning sensation, while the blood of istihadha is corrupt and cold.”
At this, she turned to her servant and said, “Do you think he was once a woman?”