"If it is menstrual blood then it is blood that is black and recognizable, so stop prying, and if it is other than that then perform Wudu', for it is just a vein."  

لَهَا رَسُولُ اللَّهِ ﷺ إِذَا كَانَ دَمُ الْحَيْضِ فَإِنَّهُ دَمٌ أَسْوَدُ يُعْرَفُ فَأَمْسِكِي عَنِ الصَّلاَةِ وَإِذَا كَانَ الآخَرُ فَتَوَضَّئِي فَإِنَّمَا هُوَ عِرْقٌ قَالَ مُحَمَّدُ بْنُ الْمُثَنَّى حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ هَذَا مِنْ كِتَابِهِ  

"If it is menstrual blood then it is blood that is black and recognizable, so stop praying, and if it is other than that then perform Wudu', for it is just a vein."  

لَهَا رَسُولُ اللَّهِ ﷺ إِذَا كَانَ دَمُ الْحَيْضِ فَإِنَّهُ دَمٌ أَسْوَدُ يُعْرَفُ فَأَمْسِكِي عَنِ الصَّلاَةِ فَإِذَا كَانَ الآخَرُ فَتَوَضَّئِي فَإِنَّمَا هُوَ عِرْقٌ  

Urwah ibn az-Zubayr reported from Fatimah daughter of AbuHubaysh that her blood kept flowing, so the Prophet ﷺ said to her: When the blood of the menses comes, it is black blood which can be recognised; so when that comes, refrain from prayer; but when a different type of blood comes, perform ablution and pray, for it is (due only to) a vein. Abu Dawud said: Ibn al-Muthanna narrates this tradition from his book on the authority of Ibn 'Adi in a similar way. Later on he transmitted it to us from his memory: Muhammad b. 'Amr reported to us from al-Zuhri from 'Urwah on the authority of 'Aishah who said: Fatimah used to have her blood flowing. He then reported the tradition conveying the same meaning. Abu Dawud said: Anas b. Sirin reported from Ibn 'Abbas about the woman who has a prolonged flow of blood. He said: If she sees thick blood, she should not pray; if she finds herself purified even for a moment, she should was an pray. Makhul said: Menses are not hidden from women. Their blood is black and thick. When it (blackness and thickness) goes away and there appears yellowness and liquidness, that is the flow of blood (from vein). She should wash and pray. Abu Dawud said: This tradition has been transmitted by Sa'id b. al-Musayyab through a different chain of narrators, saying: The woman who has a prolonged flow of blood should abandon prayer when the menstruation begins; when it is finished, she should wash and pray. Sumayy and others have also reported it from Sa'id b. al-Musayyab. This version adds: She should refrain (from prayer) during her menstrual period. Hammad b. Salamah has reported it similarly from Yahya b. Sa'id on the authority of Sa'id b. al-Musayyab. Abu Dawud said: Yunus has reported from Al-Hasan: When the bleeding of a menstruating woman extends (beyond the normal period), she should refrain (from prayer), after her menses are over, for one or two days. Now she becomes the woman who has a prolonged flow of blood. Al-Taimi reported from Qatadah: If her menstrual period is prolonged by five days, she should pray. Al-Taimi said: I kept on reducing (the number of days) until I reached two days. He said: If the period extends by two days, they will be counted from the menstrual period. When Ibn Sirin was questioned about it, he said: Women have better knowledge of that.  

لَهَا النَّبِيُّ ﷺ إِذَا كَانَ دَمُ الْحَيْضَةِ فَإِنَّهُ دَمٌ أَسْوَدُ يُعْرَفُ فَإِذَا كَانَ ذَلِكَ فَأَمْسِكِي عَنِ الصَّلاَةِ فَإِذَا كَانَ الآخَرُ فَتَوَضَّئِي وَصَلِّي فَإِنَّمَا هُوَ عِرْقٌ 1  

When the blood of menses comes, it is black blood with can be recognized; so when that comes, refrain from prayer, but when a different type comes, perform ablution and pray. Abu Dawud said: Ibn al-Muthanna said: Ibn 'Adi narrated this tradition from his memory on the authority of 'Urwah from 'Aishah. Abu Dawud said: This tradition has also been transmitted by al-'Ala b. al-Musayyab and Shu'bah from al-Hakam on the authority of Abu Ja'far. Al-'Ala reported it as a statement of the Prophet ﷺ, and Shu'bah as a statement of Abu Ja'far, saying: She should perform ablution for every prayer.  

لَهَا النَّبِيُّ ﷺ إِذَا كَانَ دَمُ الْحَيْضِ فَإِنَّهُ دَمٌ أَسْوَدُ يُعْرَفُ فَإِذَا كَانَ ذَلِكَ فَأَمْسِكِي عَنِ الصَّلاَةِ فَإِذَا كَانَ الآخَرُ فَتَوَضَّئِي وَصَلِّي  

[Machine] The Prophet ﷺ said to her, "Indeed, the blood of menstruation is black and recognizable. So if that is the case, then refrain from praying. And if it is the other [type of blood], then perform ablution and pray, for it is only a vein." Abdullah said: "I heard my father say that Ibn Abi 'Adi narrated to us through him from Aisha, then he left it."  

لَهَا النَّبِيُّ ﷺ إِنَّ دَمَ الْحَيْضَةِ أَسْوَدُ يُعْرَفُ فَإِذَا كَانَ ذَلِكَ فَأَمْسِكِي عَنِ الصَّلَاةِ وَإِذَا كَانَ الْآخَرَ فَتَوَضَّئِي وَصَلِّي فَإِنَّمَا هُوَ عِرْقٌ قَالَ عَبْدُ اللهِ سَمِعْتُ أَبِي يَقُولُ كَانَ ابْنُ أَبِي عَدِيٍّ حَدَّثَنَا بِهِ عَنْ عَائِشَةَ ثُمَّ تَرَكَهُ  

[Machine] The Prophet ﷺ said, "When it is the blood of menstruation, it is known to be black. So if it is that, then refrain from prayer. And when it is the other one, then perform ablution and pray, as it is only a vein." Ibn Al-Muthanna said, "Ibn Abi Adi mentioned this in his book like this, then he mentioned it again after memorizing it." Muhammad bin Amr narrated from Az-Zuhri from Urwah from Aisha that Fatimah used to experience postpartum bleeding, and he mentioned its meaning.  

لَهَا النَّبِيُّ ﷺ إِذَا كَانَ دَمُ الْحَيْضِ فَإِنَّهُ دَمٌ أَسْوَدُ يُعْرَفُ فَإِذَا كَانَ ذَلِكَ فَأَمْسِكِي عَنِ الصَّلَاةِ وَإِذَا كَانَ الْآخَرُ فَتَوَضَّئِي وَصَلِّي فَإِنَّمَا هُوَ عِرْقٌ قَالَ ابْنُ الْمُثَنَّى حَدَّثَنَا بِهِ ابْنُ أَبِي عَدِيٍّ مِنْ كِتَابِهِ هَكَذَا ثُمَّ حَدَّثَنَا بَعْدُ حِفْظًا قَالَ ثنا مُحَمَّدُ بْنُ عَمْرٍو عَنِ الزُّهْرِيِّ عَنْ عُرْوَةَ عَنْ عَائِشَةَ أَنَّ فَاطِمَةَ كَانَتْ تُسْتَحَاضُ فَذَكَرَ مَعْنَاهُ  

Urwah ibn az-Zubayr reported from Fatimah daughter of AbuHubaysh that her blood kept flowing, so the Prophet ﷺ said to her: When the blood of the menses comes, it is black blood which can be recognised; so when that comes, refrain from prayer; but when a different type of blood comes, perform ablution and pray, for it is (due only to) a vein. Abu Dawud said: Ibn al-Muthanna narrates this tradition from his book on the authority of Ibn 'Adi in a similar way. Later on he transmitted it to us from his memory: Muhammad b. 'Amr reported to us from al-Zuhri from 'Urwah on the authority of 'Aishah who said: Fatimah used to have her blood flowing. He then reported the tradition conveying the same meaning. Abu Dawud said: Anas b. Sirin reported from Ibn 'Abbas about the woman who has a prolonged flow of blood. He said: If she sees thick blood, she should not pray; if she finds herself purified even for a moment, she should was an pray. Makhul said: Menses are not hidden from women. Their blood is black and thick. When it (blackness and thickness) goes away and there appears yellowness and liquidness, that is the flow of blood (from vein). She should wash and pray. Abu Dawud said: This tradition has been transmitted by Sa'id b. al-Musayyab through a different chain of narrators, saying: The woman who has a prolonged flow of blood should abandon prayer when the menstruation begins; when it is finished, she should wash and pray. Sumayy and others have also reported it from Sa'id b. al-Musayyab. This version adds: She should refrain (from prayer) during her menstrual period. Hammad b. Salamah has reported it similarly from Yahya b. Sa'id on the authority of Sa'id b. al-Musayyab. Abu Dawud said: Yunus has reported from Al-Hasan: When the bleeding of a menstruating woman extends (beyond the normal period), she should refrain (from prayer), after her menses are over, for one or two days. Now she becomes the woman who has a prolonged flow of blood. Al-Taimi reported from Qatadah: If her menstrual period is prolonged by five days, she should pray. Al-Taimi said: I kept on reducing (the number of days) until I reached two days. He said: If the period extends by two days, they will be counted from the menstrual period. When Ibn Sirin was questioned about it, he said: Women have better knowledge of that. (Using translation from Abū Dāʾūd 286)   

"إذا كانَ دَمُ الحَيْضةِ فإنَّه دمٌ أسودُ يُعرفُ؛ فإِذا كان كذلك فإمْسِكى عنْ الصَّلاةِ، وإذا كانَ الآخَرُ فَتَوَضَّئ وصَلِّي فإنما هو عِرقٌ ".