הלכה אויף דברים 22:13

Before the giving of the Torah, it would be that if a man happened upon a woman in the marketplace and they wanted to marry each other, he would bring her into his house and consummate the marriage between them privately, and she would be his wife. Once the Torah was given, Israel was commanded that if a man wanted to marry a woman, he would acquire her first through witnesses, and afterwards she would be his wife, as it says, "When a man takes a woman and comes to (sleeps with) her..." (Deuteronomy 22:13).

To take a wife by the sacrament of marriage, as it is said, “When a man take a wife and marry her” (Deut. 24:1).

That one who defames his wife’s honour (by false charges of inchastity before marriage) must live with her all his lifetime, as it is said, “And she shall be his wife (he may not put her away all his days)” (Deut. 22:19).