Was incest permissible at the beginning of humanity's creation, given that all humans are descendants of Adam, and when was it forbidden?

The marriage of Adam's children to one another was a necessity for the continuation of progeny. Each male was born with a female, and the boy from the first womb was married to the girl from the second womb, and vice versa. Marriage within the same womb was forbidden. The Quran and Sunnah do not mention the history of the prohibition of incestuous marriages. However, the Quran broadly prohibited this in Surah An-Nisa (4:23) to include fosterage, the father's wife, and marrying two sisters simultaneously. All that has been narrated regarding the history of the prohibition of incestuous marriages in previous legislations is speculative and relies on transmissions from the People of the Book, which may subject it to errors and delusions. Knowledge of this history is not beneficial. What is important is that Allah Almighty has definitively prohibited incestuous marriage.