they ask about the monthly course. say it is a state of impurity so keep apart from women during their monthly course and do not go near them until they are clean. when they have cleansed themselves then you may go to them in the manner allah has enjoined you. most surely allah loves those people who refrain from evil and keep themselves pure and clean.
ويسألونك عن المحيض قل هو أذى فاعتزلوا النساء في المحيض ولا تقربوهن حتى يطهرن فإذا تطهرن فأتوهن من حيث أمركم الله إن الله يحب التوابين ويحب المتطهرين