At this point, we need to learn the definition of some general terms in Islamic fiqh which come up in many subject areas, including the one at hand.
With respect to marriage, there are four different kinds of conditions which must be met:
In this category, there are conditions concerning the two who are getting married as well as the form in which the contract takes place.
The two people must meet the qualification of legal competence, i.e, they must be adult and sane. If they are not, the marriage will be invalid.
Secondly, the woman cannot be from those categories of women that are forbidden for a man to marry. For example, suppose a man married a woman and later discovered that they had been breastfed by the same woman. In this case, it is as if the marriage never took place because those two were not qualified or allowed to marry each other and the marriage becomes null and void.
There is near complete agreement on the following conditions relating to the transaction of the marriage contract:
Note that the custom of saying "I accept" three times common in some Muslim cultures has no legal significance. Once the first "I accept" has been uttered, everything after that is meaningless - whether positive or negative.
This is where one party states a stipulation binding on the other party for specific reasons or goals. The offer/acceptance are tied to this stipulation by mention. There is a difference of opinion among the scholars concerning the validity of conditions of this nature.
Conditions of contracts are two types: 1) those imposed directly by the shari'a and 2) those drawn up by one or more of the parties. When any contract is entered into, the first type of conditions are covered automatically even if they are not stated in the contract.
It is a general principle in fiqh that customs can take the status of law. It becomes understood that people are going to behave in a certain fashion. Since that is understood, one party has the right to ask it of the other even if it is not stated in the contract. In the area of marriage, there are some stipulations that are known by custom. These do not have to be mentioned in the contract to be considered binding. However, there are some strict conditions that must be met before a customary act is considered something equivalent to a legal stipulation. These conditions are as follows:
Any condition which contradicts, compromises or nullifies the main goals and purposes of the marriage contract itself are rejected and, even if stated, are of no legal consequence. For example conditions which state that the woman receives no dowry or that he does not have to support her or that they will not consummate the marriage are all null and void and of no effect whatsoever.
Such conditions must be stipulated and agreed upon at or before the time of the offer/acceptance. Even those scholars who accept such stipulations do not accept them if they are made after the offer/acceptance.
There are two types of sound and acceptable stipulations:
Generally speaking, Muslims must comply with any agreements that they make. Allah said about the believers:
{...Wa al-moofoona fi 'ahdihim idhaa 'aahadoo...}
{...And those who fulfill their pacts when they make one...} Al-Baqara:177{Yaa ayyuhaa alladhina aamanoo aufoo bi al-'uqood...}
{O you who believe fulfill your contracts...} Al-Ma'idah:1
The Prophet (sas) said:
"Al-muslimoona 'alaa shurootihim."
"Muslims are bound by their stipulations." Abu Daud & Al-Hakim (sahih)
During the time of Umar ibn Al-Khattab, a man married a woman upon the condition that he would not move her from his house. The time came when he wanted to move her. They took their dispute to Umar and he said: "She has the right to her stipulation." The man said, "In that case, they will certainly end the marriage." He said, "The rights are broken off due to the stipulations." This was the view of many of the Companions, Followers and scholars including Saad ibn Abi Waqqas, Mu'awiyah, Amr ibn Al-Aas, Shuraih, Umar ibn Abdul Aziz, Tawoos, Al-Awzaa'i and Ishaq.
There is another opinion which says that external stipulations - those not covered by the nature of the contract itself - carry no weight and need not be met. This was the opinion of Abu Hanifa, Ash-Shafi'i, Malik, Az-Zuhri, Qatada, Al-Laith, Ath-Thauri, Ibn Al-Mundhir and has been narrated from Ali.
"Kullu shartin laisa fiy kitaabi Allahi fahuwa baatil wa in kaana mi'atu shartin."
"Every stipultion which is not in the book of Allah is void even if it be one hundred stipulations." Muslim & Bukhari
They also cite the following extension to the hadith mentioned earlier about stipulations:
"Al-Muslimoon 'alaa shurootihim illa shartin ahalla haraaman au harrama halaalan."
"Muslims are bound by their stipulations except for a stipulation which makes the unlawful lawful or makes the lawful unlawful."
However, this version of the hadith with the added sentence is weak and cannot be used as evidence. As for the hadith mentioned earlier that "The conditions which you have the most duty to fulfill are those by which you have made marital relations lawful.", they claim that this only applies to the conditions which are essential parts of the nature of the contract itself.
The scholars who permit such stipulations in the marriage contract have responded to the above. As for the hadith "Every stipulations which is not in the book of Allah...", they say that for a woman's wali to make some conditions to her advantage is something permissible and does not go against the Book of Allah.
Actually, such conditions do not violate the Book of Allah and do not make anything forbidden permissible, etc. They simply give the woman the right to annul the marriage if the condition is not satisfied.
Also, there remains no real meaning to the hadith "The conditions which you have the most duty to fulfill..." if one says that it only applies to conditions that are already in force due to the nature of the contract anyway.
This discussion boils down to the understanding of two seemingly contradictory hadith:
"Every stipulation which is not in the book of Allah is void even if it be one hundred stipulations." Muslim & Bukhari
"The conditions which you have the most duty to fulfill are those by which you have made marital relations lawful." Bukhari & Muslim
It seems clear from the second hadith along with the fatwa of Umar mentioned earlier that there is some room for adding stipulations to a marriage contract. It also seems clear from the first hadith that there are limits on what can be stipulated. Specifically, any stipulations which go against the basic goals and principles of the marriage contract and not allowed and, if stated, are null and void. Thus, the only remaining problem is understanding exactly how this principle applies in practical situations.
For those scholars who don't accept such external stipulations at all, they have no effect, are not binding, and don't affect the validity of the underlying contract. For those who accept them, they give the woman the option to annul the marriage upon he request if the condition is violated. We only mention the woman because the man can divorce at any time with or without a particular cause and so has no need of such an option. Notice that even in the fatwa of Umar, he didn't require the man to fulfill the condition, rather he allowed that she could end the marriage if she so demanded.
Even those who accept these stipulations all agree that certain conditions are not allowed. Among them are the following: