Is it permissible for the husband to prevent his wife from working or to take her salary or part of it, knowing that he agreed to her continuing to work before marriage and in front of witnesses?

Scholars have differed on the obligation of the husband to fulfill conditions stipulated by the wife or her guardian before or during the marriage contract, such as continuing in a specific job or not marrying another woman, falling into two opinions: The majority (Malik, Al-Shafi'i, Abu Hanifa, Al-Layth, and Al-Thawri) do not obligate this, while Ahmad ibn Hanbal, Al-Awza'i, and others obligated it. This latter opinion is the more preponderant, based on the Almighty's saying: (O you who have believed, fulfill [your] contracts) and the Prophet's (peace be upon him) saying: "The most worthy of conditions to be fulfilled are those by which you make intimate relations lawful."

As for the husband stipulating a sum of money in return for allowing her to work, he may take it. If he did not stipulate anything, he should not take it. It is commendable to assist the husband if he is in need.