When does a woman's waiting period begin if she is divorced while menstruating?

Question:
Following the opinion that divorce takes effect during menstruation, and given that those who hold this view agree that the menstrual period in which the divorce occurred is not counted in the waiting period, the question is: When does the waiting period begin? Does it begin with the first period of purity after the menstrual period in which the divorce occurred? Or when?

Answer:
It begins with the menstrual period that follows. If it is said that the divorce takes effect, it begins with the menstrual period that follows. The menstrual period in which the divorce occurred is not counted. However, the correct view is that if the divorce occurs during menstruation, it does not take effect, provided the husband knows and is aware of this, and the wife is likewise aware, if they are truthful. They all know that it is during menstruation: the correct ruling is that it does not take effect, unless a judge rules on it. If a judge rules on it, the majority of scholars consider it effective. If the judge rules on it, it is executed; otherwise, the original ruling is that it does not take effect. This is because the Prophet (peace and blessings be upon him) rebuked 'Abdullah ibn 'Umar when he divorced his wife during menstruation. He became angry with him, rebuked him, and ordered him to take his wife back, saying: in a period of purity before he touches her. This is what is prescribed. And Allah said: [Al-Talaq: 1] for their waiting periods, if they are in a state of purity, without sexual intercourse. This is the divorce for the waiting period: that it be in a state of purity in which there was no sexual intercourse, as the Exalted said: [Al-Talaq: 1].
Q: And is it counted as one divorce?
A: According to the correct view, unless a judge rules on it. If a judge rules on it, the judge's ruling resolves the disagreement, according to the majority.