Ḥayḍ, Istiḥāḍah, and Nifās
Extract from Badāʾiʿ al-Ṣanāʾiʿ by ʿAllāmah al-Kāsānī and Tuḥfat al-Fuqahāʾ by ʿAllāmah ʿAlāʾ al-Dīn al-Samarqandī
Ḥayḍ
The period of ḥayḍ
Ḥayḍ is blood that exits from the uterus over a period of time. The ʿulamāʾ differ over what that period is. Imām Mālik holds that no period is specified for ḥayḍ, neither a minimum nor a maximum. The Aḥnāf hold that the minimum period of ḥayḍ is three days with their nights, and the maximum ten days with their nights.
It is narrated from Imām Abū Yūsuf that the minimum period of ḥayḍ is two days and the maximum three days. Imām al-Shāfiʿī holds that the minimum is one day and one night and the maximum fifteen days.
The colour of the blood
If the blood is black, by consensus it counts as ḥayḍ. Red blood likewise counts as ḥayḍ for the Aḥnāf, while the Shawāfiʿ hold that only black blood is ḥayḍ.
Muddy-coloured blood counts as ḥayḍ if it appears in the final days of the period; on this, the Aḥnāf agree. If muddy blood flows at the beginning of the period, Imām Abū Ḥanīfah and Imām Muḥammad still count it as ḥayḍ; Imām Abū Yūsuf does not.
Yellowish blood is disputed among the ʿulamāʾ, but is generally counted as ḥayḍ, whether it appears at the beginning or the end of the period.
Greenish blood is treated by some as muddy blood, though there is disagreement. Others hold that muddy, yellowish or greenish blood counts as ḥayḍ without exception, save in the case of an old woman. For her, one looks to her habit: if her usual time of ḥayḍ is near, the discharge counts as ḥayḍ; if it is far off and she is not expecting to bleed, it does not.
When ḥayḍ is established
Ḥayḍ, nifās and istiḥāḍah take effect only once the blood flows from inside the private part and becomes visible outside. If the blood remains internal, none of the three is established.
Nifās
Nifās is the blood that flows after giving birth. It has no minimum period: if a woman sees blood only for a moment and it then stops, nifās has occurred and she is now pure.
For the Aḥnāf, the maximum period of nifās is forty days. For Imām al-Shāfiʿī, it is sixty. Imām Mālik holds that it is seventy.
Istiḥāḍah
Istiḥāḍah is blood that flows for less than the minimum days of ḥayḍ, or for more than the maximum days of ḥayḍ or nifās.
A mustaḥāḍah (a woman in the state of istiḥāḍah) falls into two types: the woman entering istiḥāḍah for the first time, and the woman with an established habit.
If a girl reaches puberty and sees blood for the first time, and the blood flows continuously for more than ten days, the first ten days are reckoned ḥayḍ and what follows is istiḥāḍah.
For the woman with an established habit, any blood that flows for less than ten days counts as ḥayḍ; what flows beyond ten days is istiḥāḍah.
If her habit is less than ten days and the blood flows beyond her usual count but still within ten days altogether, the whole flow is ḥayḍ and her habit is taken to have changed. If, however, the blood flows for more than ten days, then only what coincided with her habit is ḥayḍ; the surplus is istiḥāḍah.
Ruling for a woman in the state of istiḥāḍah
A woman in the state of istiḥāḍah is treated like a ṭāhirah (a pure person), with one qualification: she must perform wuḍūʾ for the waqt of every ṣalāh.