Translation:

222. They ask thee concerning women's courses. Say: They are a hurt and a pollution; so keep away from women in their courses and do not approach them until they are clean. But when they have purified themselves ye may approach them in any manner time or place ordained for you by Allah. For Allah loves those who turn to Him constantly and He loves those who keep themselves pure and clean.

Notes (Tafseer)

247. Azan: hurt, pollution. Both aspects must be remembered. Physical cleanliness and purity make for health, bodily and spiritual. But the matter should be looked at from the woman's point of view as well as the man's. To her there is danger of hurt, and she should have every consideration. In the animal world, instinct is a guide which is obeyed. Man should in this respect be better: he is often worse.

248. Haithu: A comprehensive word referring to manner, time, or place. The most delicate matters are here referred to in the most discreet and yet helpful terms. In sex morality, manner, time, and place are all important: and the highest standards are set by social laws, by our own refined instinct of mutual consideration, and above all, by the light shed by the highest Teachers form the wisdom which they receive from our Maker, Who loves purity and cleanliness in all things.