He—may Allah have mercy on him—was asked:

A man stipulates that he will not marry another woman alongside his wife, take a concubine, or move her from her home or town. If she stipulates these conditions before the marriage contract and they agree to them, but the contract makes no mention of them, are they valid and binding, requiring fulfilment just like conditions stipulated when the contract is concluded, or not?

He answered:

Praise be to Allah. Yes, they are valid and binding if the two parties have not revoked them, even if they accompanied the conclusion of the contract. This is the apparent position of Imam Abū Hanīfa, Imam Mālik, and others regarding all contracts. It is also one position within al-Shāfiʿī’s school, inferred from the issue of “the privately agreed dower and the publicly announced dower.” Mālik and Ahmad likewise apply this principle to acts of worship: according to them, an intention formed beforehand is equivalent to one formed when the act begins.

There is a second position within Ahmad’s school: stipulations made before the contract have no effect. There is also a third position, which distinguishes between a stipulation that makes the transaction itself unintended—such as an agreement that a sale is merely a sham with no reality—and a stipulation that does not prevent the transaction from being genuinely intended, such as stipulating an option to rescind or something similar.

However, the general tenor of the explicit rulings of Ahmad, the early scholars of his school, and its meticulous later scholars is that, when stipulations and prior agreements between the contracting parties have not been revoked by the time they conclude the contract, the contract takes effect