It is narrated from Sayyidah Aishah (may Allah be pleased with her) that Fatimah bint Abi Hubaysh came to the Prophet (peace and blessings be upon him) and said: I have prolonged bleeding (istihadah); I do not become pure. Shall I abandon the prayer? The Messenger of Allah (peace and blessings be upon him) said: "That is from a vein; abandon the prayer during the days of your menstruation, then take a ritual bath and pray," or words to that effect.
(b) I think that both narrations are in the wording of Abu Usamah. It has also been narrated from Abu Usamah in the wording which a group narrated, that is, concerning the coming and going of menstruation.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحيض / 1549