What is the ruling on a woman saying to her son, "By Allah, Allah will not have mercy on you from me"?

If a child disobeys his mother, her prayer against him will be answered. He must repent to Allah, seek forgiveness from his mother, serve her, and strive for her satisfaction, for in serving her lies Paradise.

As for the mother's statement, "By Allah, Allah will not have mercy on you because of me," if she means that Allah will not have mercy on him due to his disobedience, then this is true, because there is no reward for disobedience. If she means that Allah will never have mercy on him, then this is an assumption of Allah's authority, which is forbidden, as stated in the Hadith Qudsi: "Who is he who takes an oath by Me that I will not forgive so-and-so? Indeed, I have forgiven so-and-so and rendered your deed worthless." If her intention is to invoke Allah's lack of mercy upon him, she should not do so, for it is forbidden to pray against one's children.