The ruling on a man saying to another: “I have gifted you my daughter,” and her marriage to another

A brother, Abdullah ibn Nasser ibn Saif from al-Dalim, asks: A man gifted his daughter to another man, and they were conversing in a gathering without a formal contract. The daughter was ten years old at the time. After two years had passed, the situation changed, and the daughter married the son of the man to whom she had been gifted. What is the ruling in this case?
Answer: First, the gift is examined to see if it was with the daughter’s consent and in the presence of two witnesses, and if the marriage was consummated. If the daughter did not consent, or if two witnesses were not present, then the marriage is not valid. This is because it is obligatory to consult the daughter if she has reached the age of nine; it is not permissible to marry her off without her permission, and her permission is her silence. If her father did not seek her permission when he made the gift, or if he sought her permission but two witnesses were not present, then the gift and the marriage are not valid. However, if he sought her permission and she consented by silence or by speech, and two witnesses were present, then the correct view is that the marriage is valid. It is not a condition that he say, “I have married you off” or “I have given you in marriage.” Rather, if he says, “I have gifted you,” or “I have given you,” or “I have made you lawful,” it is valid if the other conditions are met and the impediments are absent. And success is from Allah. Yes...
The presenter: But in this case, after two years, he married her to the son of the man to whom she had been gifted!
The Shaykh: If the first marriage was valid, then the second marriage is invalid. If the first marriage was not valid, then the second marriage is valid. Yes...
The presenter: May Allah reward you.