عن عقبة بن عامر رضي الله عنه مرفوعاً: «إن أحَقَّ الشُّروط أن تُوفُوا به: ما استحللتم به الفروج». [صحيح] - [متفق عليه] المزيــد ...
‘Uqbah ibn ‘Āmir (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "The conditions that are the worthiest of being fulfilled are those which make sexual intercourse lawful for you." Sahih/Authentic. - [Al-Bukhari and Muslim]
Each spouse has his/her own purposes in getting married, thus the spouse may stipulate conditions (to serve these purposes), which become binding upon the other, apart from the conditions that are essential for the validity of marriage. Since it is by virtue of these conditions that enjoyment of sexual intercourse becomes lawful, they have great sanctity, and the Islamic law urged fulfilling them.
It shows the obligation to fulfill the conditions each of the spouses is committed to towards the other, like when the woman stipulates an addition in the dowry or a certain place for habitation, and when the husband stipulates virginity or good lineage.
The generality of the Hadīth is specified by the other Hadīth that states: “It is not permissible for a woman to ask for her co-wife to be divorced."
Fulfilling the conditions of marriage is more emphasized than fulfilling other conditions since they are stipulated in return for making sexual intercourse with the wife lawful.
The rights due on each spouse for the other - like the rights of financial maintenance, sexual enjoyment and spending the night as due for the wife, and the right of sexual enjoyment as due to the husband - are not bound to a certain limit but rather reliant on custom.
Conditions in marriage have two cases: 1. Valid conditions: they do not violate the requirements of the marriage contract and are aimed at a valid purpose. 2. Invalid conditions: They violate the requirements of the marriage contract. The criteria for judging such conditions and other similar ones is the saying of the Messenger of Allah (may Allah’s peace and blessings be upon him): “Muslims must keep to the conditions they have made, except for a condition which makes unlawful something which is lawful or makes lawful something which is unlawful.” There is no difference in this regard whether the condition takes place before or during the contract.