All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Qar’ in the Arabic language refers to menses as well as purity (following menses), so it is among the words which has a multiple-meaning.
However, the scholars differed in opinion in regard to the meaning of Quroo’ (plural of Qar’) in the saying of Allaah (which means): {Divorced women remain in waiting [i.e. do not remarry] for three Quroo’.}[Quran 2:228]; so some said that it means menses, and some said that it means purity.
In our view, the preponderant opinion is that Qar’ refers to menses, and among the pieces of evidence for this opinion from the Ahaadeeth is the saying of the Prophet, sallallaahu ‘alayhi wa sallam, about the menstruating woman: "She should refrain from praying during the days of her Quroo’.” [Abu Daawood]
The Prophet, sallallaahu ‘alayhi wa sallam, also said to Faatimah Bint Abi Hubaysh : "Look, when your Qar’ comes, do not pray, and when your Qar’ is over, then perform Ghusl and then pray in the period between one Qar’ and another.” [An-Nasaa’i]
The Prophet, sallallaahu ‘alayhi wa sallam, also said: "The divorce of a slave woman is two divorces (i.e. two times of divorce) and her Quroo’ (of her waiting period) are two menses.” [Abu Daawood]
What we can notice from these three Ahaadeeth is that the Prophet, sallallaahu ‘alayhi wa sallam, did not refer to Qar’ except with the meaning of menses.
Besides, Sharh Al-Mumti’ of Shaykh Ibn ‘Uthaymeen reads: “… Based on this, we say: The correct view is that Quroo’ are menses, and so the saying of Allaah {… three Quroo’} means three menses.”
Moreover, Zaad Al-Ma’aad authored by Ibn Al-Qayyim reads: “If we presume that the word Qar’ in this verse means only one of the two meanings and not both of them, then it predominantly refers to menses for many reasons: Firstly, for what has been previously discussed, and secondly, using the word Qar’ to mean menses is more appropriate than using it to mean purity, as they (the scholars) usually mention it (menses) as an interpretation of its wording, and then they say: “it was said / so and so said / it is said: it refers to “purity” or “it refers as well to purity”…. Then he said: The second evidence: the word Qar’ was not used in the words of The Law Maker (i.e. Allaah The Almighty or His Prophet, sallallaahu ‘alayhi wa sallam) except for menses, and it is not used even in one single case to mean purity, so interpreting it in the verse to mean what is usually meant in the words of The Law Maker is more appropriate; rather, it has to be interpreted in this way … etc.”
Allaah Knows best.