What is the ruling of Islamic law regarding the marriage of a young man who has not completed his studies and whose mother has refused, while his father has agreed, knowing that the young man is committed and suitable?

One of the purposes of marriage is chastity, and one should hasten to it. Studying is not a barrier to it, neither legally nor naturally. The young man should convince his mother to agree to his marriage. If she insists on refusing, the default is that obeying her is obligatory, unless there is a fear of fitna. As for the young woman, if the young man prefers to obey his mother or if his marriage to her is not facilitated, she should not allow herself to pine for him. Let her remember: "And perhaps you hate a thing and it is good for you." And she must cut off any relationship with him because he is a stranger to her.