2/222 — The choice of the word
The choice of the word is worth recording. The verse does not use here a word stating impurity, filth, or a state to be kept away from; it uses a word stating discomfort.
It is widely transmitted that in the classical commentaries this word is explained in respect of the trouble it gives the woman.
As historical background this is transmitted: in that period, in some communities there were practices such as putting a menstruating woman out of the house and not eating with her. The verse's limiting of the boundary to a single act has been understood as doing away with that wide exclusion.
I do not enter into the legal rulings; the details the schools derive from this verse differ, and what is conveyed here is the linguistic side of the word.
إِنَّ ٱللَّهَ يُحِبُّ ٱلتَّوَّٰبِينَ وَيُحِبُّ ٱلْمُتَطَهِّرِينَ — the verse closes the discussion of purity with a sentence about love. The pattern مُتَطَهِّرِين (Form V) means one who purifies himself; that is, the act belongs to the person.