Ruling on a man who married his illegitimate daughter without knowing it

The third message in this episode came from Sudan, from Port Sudan, from the questioner Awaj Muhammad Hamad. He says in his message: There was a man who had a relationship with a woman without marriage, and she bore him a daughter. They separated for a long period. Then he proposed to a girl he had met, and she agreed to marry him, so he married her. After a period, he discovered that she was his illegitimate daughter from that woman. What is the ruling in Islam regarding this? And what should he do?
Answer: First: He must repent for the fornication he committed, turn back to Allah, feel remorse, abandon the sin, be sincere in that, seek forgiveness frequently, and do good deeds.
Second: This marriage is invalid. As long as he knows that she is his daughter from fornication, the majority of scholars hold that it is an invalid marriage; because she was created from his semen, it is not permissible for him to marry her. Even if she is an illegitimate daughter, an illegitimate daughter, she falls under the general meaning of the statement of the Exalted and Majestic: [Surat al-Nisa: 23]. She is an illegitimate daughter created from his semen, so her marriage is invalid, she is not attributed to him, and she does not become a mahram (a relative one may not marry) for him. However, her marriage is invalid according to the scholars; because she was created from his illegitimate semen, it is forbidden for him to marry her, and she is not attributed to him. Yes.
The presenter: May Allah reward you.