(a) It is narrated from Sayyidah Aishah (may Allah be pleased with her) that a woman with prolonged bleeding (istihadah) should abandon the prayer during the days of her menstruation, then take a ritual bath and perform ablution for every prayer.
(b) Al-Sha'bi (may Allah have mercy on him) says: She does not fast, and her husband does not have intercourse with her.
(c) So the statement about intercourse with her goes back to the words of al-Sha'bi, as Ahmad bin Hanbal said, and we have left it because of the evidence mentioned earlier that intercourse with her is permissible once her menstruation has ended and she has taken a ritual bath.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحيض / 1564