1,428. Before the Torah was Given; The Arayos

Hilchos Ishus 1:4

Before the Torah was given, if a man met a woman and both parties were amenable, he could give her money, they could engage in intimate relations outside of marriage, and there would be no permanent bond between them. Such a woman was called kadeisha. [Simply speaking, this is a prostitute but there are levels of nuance missing so we will continue to use the term kadeisha.] When the Torah was given, engaging in relations with a kadeisha became prohibited as per Deuteronomy 23:18, “There shall not be a kadeisha among the children of Israel.” Accordingly, if a man were to engage in intimate relations with a woman in order to satisfy his lust, without undergoing the kiddushin process, he would receive lashes for violating the Torah prohibition against having relations with a kadeisha.

Hilchos Ishus 1:5

The Torah inherently prohibits engaging in intimate relations with some people and engaging in relations with one of these people would make one liable to the penalty of kareis (spiritual excision). These people are listed in the Torah in parshas Acharei Mos (Leviticus 18) and they include such relationships as a one’s mother, his sister, his daughter, etc. These prohibited relationships are called “arayos”; each one individually is called an “ervah.”