The ruling on proposing to a woman who has already been proposed to by another

The questioner:
He says: What is the ruling on a man who proposes to a woman while knowing that she has already been proposed to by another person, and they accepted his proposal? Should he marry her or leave her?

The Shaykh:
If he knew at the time of acceptance or at the time of the proposal that she had already been proposed to, it is forbidden for him and not permissible for him to do so, because the Prophet (peace and blessings be upon him) forbade a man from proposing to a woman who has already been proposed to by his brother. It is not permissible until the first suitor withdraws his proposal or gives permission. If the suitor gives permission, there is no harm. Or if the suitor withdraws and does not accept, there is no harm in you proceeding.

The questioner:
But should he proceed or not? He says that they gave her to him while he knew of this.

The Shaykh:
He must ask the first suitor for permission. If he gives him permission, there is no harm. Yes.