“Consider the painful life that Jesus Christ led in the womb of his Mother, and the long‑confined and dark imprisonment that he suffered there for nine months. Other infants are indeed in the same state; but they do not feel the miseries of it, because they do not know them. But Jesus knew them well, because from the first moment of his life he had the perfect use of reason….The womb of Mary was therefore, to our Redeemer a voluntary prison, because it was a prison of love. But it was also not an unjust prison: he was indeed innocent himself, but he had offered himself to pay our debts and to satisfy for our crimes. It was therefore only reasonable for the divine justice to keep him thus imprisoned, and so begin to exact from him the due satisfaction.
Behold the state to which the Son of God reduces himself for the love of men, he deprives himself of his liberty and puts himself in chains, to deliver us from the chains of hell.” St. Alphonsus de Liguori,The Incarnation, Birth and Infancy of Jesus Christ