Is what the husband's father did considered an injustice to his son, or is the husband the one who wronged his father, based on the unfulfilled promises and the difficult living conditions that resulted from that?

A parent's gift to one child over others is impermissible, and equalization is obligatory, according to the preponderant view of jurists. However, some have held it permissible to favor one child if there is a valid justification. Marriage allows for favoring the needy child with a portion of a gift, and the need can be met by gifting the usufruct without transferring ownership of the property. Sheikh Ibn Uthaymeen said: "If one of the children needs a car and the others do not, we do not give the needy child a car in his name; rather, the car remains in the father's name. This meets his need through his use of it, and if the father dies, it returns to the estate."

Jurists have differed on the ruling regarding fulfilling a promise. The correct view is that it is binding if the promisee incurs a burden as a result. It becomes legally binding if it was contingent on a reason and the promisee incurred a burden as a result of the promise. The effect of the binding nature is determined either by fulfilling the promise or compensating for the harm.

If the promise was what motivated the husband to marry, and the father failed to fulfill it without a valid শরঈ excuse, then he has acted wrongly. However, the son must still honor his father in all circumstances.