Why is the waiting period of divorce three months and the widow's four months and ten days?

Answer

In the name of Allah, be advised, that the rulings of marriage, divorce and waiting periods are all pure rulings of worship. These are similar to the rules of the number of the praying units [rikaat] of the daily prayers, such as the dawn prayer has two praying units, the noon and the afternoon have four each, and the sunset has three. Each praying unit has one kneeling and two prostration. In the same principle, we cannot realize the reason of these numbers. We are – as Muslims – have to submit and be humble to the rulings of Allah Almighty. Allah is the Guide.