The ruling on a mother preventing her son from fasting one day and breaking the fast the next

Question:
He says: Honorable Shaykh, may Allah grant you success, a young man wants to fast one day and break the fast the next, because that is a recommended practice (sunnah), and because the Prophet (peace and blessings be upon him) commanded one of the Companions to do so, and commanded the one who could not afford marriage to fast. Does his mother have the right to prevent him from doing so on the grounds that it is difficult for him?

Answer:
And his fasting weakens him from serving her and fulfilling her rights. Her right is obligatory, so he does not fast; he is dutiful to his mother. However, if he is fulfilling his mother's right, and she is only preventing him out of concern for him and mercy toward him, then he should convince her. It is better that he convince her and say, “I am not burdened by hardship, and this is good for me and for you, and there is reward in it.” So, mutual understanding is better.