How long is the normal monthly time of separation (niddah) for a woman?
Answer From The Annual Reading Schedule - Week 27 Notes For Leviticus: 7 days (Leviticus 15:19). The later verses, discussing about counting 7 days from the time her discharge stop in verse 28, are referring to bleeding beyond or outside of that normal 7 day period. The reason we know this for certain is because in verse 29-30 a sin offering is required. If a woman had to give a sin offering every time she had a period, those who live far away from the Temple would never be able to even be at home because they would always be traveling to do a sin offering every single month. However, this offering, as well as the counting of 7 days from the time her discharge stops, are both referring to bleeding that occurs outside the normal 7-day period of separation (niddah).
