The obligation of the son after the marriage provision is fulfilled.
General Chapter
Al-Mughni
Book of Maintenance (Nafaqāt)
Primary text
If the son marries the father to a wife or procures a female slave for him, the son remains responsible for their maintenance (nafaqah). If the father later becomes wealthy (maysir), the son cannot reclaim what he spent or seek compensation for the wife provided, because the expenditure was made during a time when the obligation was incumbent upon him, similar to Zakat, which cannot be reclaimed.
Supporting text
If the wife whom the son arranged is divorced, or the female slave is manumitted by the son, the son is not obligated to arrange another marriage or provide another slave, because the father forfeited that benefit himself. However, if the wife or slave dies, the son must provide the marriage provision again because the loss was not caused by the father.