✅ Answer: Please pay attention to the following narrations:

1 عَنْ مُعَاوِيَةَ بْنِ عَمَّارٍ قَالَ: قَالَ أَبُو عَبْدِ اللَّهِ إِنَّ دَمَ الِاسْتِحَاضَةِ وَ الْحَيْضِ لَيْسَ يَخْرُجَانِ مِنْ مَكَانٍ وَاحِدٍ إِنَّ دَمَ الِاسْتِحَاضَةِ بَارِدٌ وَ إِنَّ دَمَ الْحَيْضِ حَارٌّ.

📚 Al-Kafi, Vol. 3, p. 91

Imam Sadiq (peace be upon him) said: 'Hayd (menstrual) blood and Istihadah (irregular) blood do not come from the same place. Istihadah blood is cold, and Hayd blood is hot!'

2 عَنْ حَفْصِ بْنِ الْبَخْتَرِيِّ قَالَ: دَخَلَتْ عَلَى أَبِي عَبْدِ اللَّهِ امْرَأَةٌ فَسَأَلَتْهُ عَنِ الْمَرْأَةِ يَسْتَمِرُّ بِهَا الدَّمُ فَلَا تَدْرِي حَيْضٌ هُوَ أَوْ غَيْرُهُ قَالَ فَقَالَ لَهَا إِنَّ دَمَ الْحَيْضِ حَارٌّ عَبِيطٌ أَسْوَدُ لَهُ دَفْعٌ وَ حَرَارَةٌ وَ دَمُ الِاسْتِحَاضَةِ أَصْفَرُ بَارِدٌ فَإِذَا كَانَ لِلدَّمِ حَرَارَةٌ وَ دَفْعٌ وَ سَوَادٌ فَلْتَدَعِ الصَّلَاةَ قَالَ فَخَرَجَتْ وَ هِيَ تَقُولُ وَ اللَّهِ أَنْ لَوْ كَانَ امْرَأَةً مَا زَادَ عَلَى هَذَا.

📚 Al-Kafi, Vol. 3, p. 91

Hafs said: 'A woman came to Imam Sadiq (peace be upon him) and asked about a woman whose bleeding continues, and she does not know if it is Hayd or not.'

The Imam said to her: 'Hayd blood is hot, fresh, black, and has pressure and heat. Istihadah blood is yellow and cold. So, when the blood has pressure, heat, and blackness, she must stop praying!'

The woman left, saying: 'If he were a woman, he would not have added anything to this statement!'

3 عَنْ إِسْحَاقَ بْنِ جَرِيرٍ قَالَ: سَأَلَتْنِي امْرَأَةٌ مِنَّا أَنْ أُدْخِلَهَا عَلَى أَبِي عَبْدِ اللَّهِ..... دَمُ الْحَيْضِ لَيْسَ بِهِ خَفَاءٌ هُوَ دَمٌ حَارٌّ تَجِدُ لَهُ حُرْقَةً وَ دَمُ الِاسْتِحَاضَةِ دَمٌ فَاسِدٌ بَارِدٌ قَالَ فَالْتَفَتَتْ إِلَى مَوْلَاتِهَا فَقَالَتْ أَ تَرَاهُ كَانَ امْرَأَةً مَرَّةً.

📚 Al-Kafi, Vol. 3, p. 91

Ishaq ibn Jarir said: 'A woman from among us asked me to bring her to Imam Sadiq (peace be upon him)... until Imam Sadiq (peace be upon him) said: 'Hayd blood is not hidden; it is a hot blood from which you feel a burning sensation, and Istihadah blood is corrupt (not fresh) and cold!''

The narrator said: 'The woman turned to her master and said: 'Do you think he was a woman at one time?!''

4 عَنْ مُعَاوِيَةَ بْنِ عَمَّارٍ عَنْ أَبِي عَبْدِ اللَّهِ قَالَ: أَقَلُّ مَا يَكُونُ الْحَيْضُ ثَلَاثَةُ أَيَّامٍ وَ أَكْثَرُهُ مَا يَكُونُ عَشَرَةُ أَيَّامٍ.

📚 Al-Kafi, Vol. 3, p. 75

Imam Sadiq (peace be upon him) said: 'The minimum amount of Hayd is three days, and the maximum is ten days!'

5 عَنْ يُونُسَ عَنْ بَعْضِ رِجَالِهِ عَنْ أَبِي عَبْدِ اللَّهِ قَالَ: أَدْنَى الطُّهْرِ عَشَرَةُ أَيَّامٍ وَ ذَكَرَ الْحَدِيثَ إِلَى أَنْ قَالَ وَ لَا يَكُونُ الطُّهْرُ أَقَلَّ مِنْ عَشَرَةِ أَيَّامٍ.

📚 Al-Kafi, Vol. 3, p. 76

Imam Sadiq (peace be upon him) said: 'The minimum period of purity is ten days...' until he said: 'The period of a woman's purity is not less than ten days!'

✅ The above narrations are clear in response to the question. It should be known that understanding the general principles of Hayd and Istihadah is necessary for recognizing their various rulings, whether for a novice (Mubtadi'ah), which is someone who sees blood for the first time, or for someone with a set number (Dhat al-Adad), who has specific days for Hayd, or for a disordered woman (Mudtaribah), whose time of Hayd is not distinguishable from her time of purity.

The details of using the above principles and others have been stated in different rulings, and the above Hadith are a prelude to correctly understanding those rulings.

اللَّهُمَّ صَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ

وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ

Characteristics of Hayd and Istihadah Blood