By this betrothing she had actually engaged herself to another man, and was in some sort his with, and therefore is sometimes so called, as Genesis 29:21 Matthew 1:20.
Related Commentaries of Deuteronomy 22:23
Deuteronomy 22:23
23 If a damsel that is a virgin be betrothed unto an husband, and a man find her in the city, and lie with her;