What is the ruling on using birth control pills without the husband's knowledge, given that he had previously agreed to them but then prohibited them, and knowing that they have three children and he does not wish to have more children at present?

It is not permissible for the wife to prevent pregnancy except with the husband's permission or if there is a proven harm. It is not permissible to prevent procreation altogether except out of necessity. It is not appropriate to temporarily stop it without a benefit, and a condition of not having children is void, whether stipulated before or after the marriage contract. The spouses should be keen on the stability of the family and cooperation. It is not permissible for the wife to leave her husband's house except with his permission or for a legitimate excuse.