2,147. The Consequence of Intermarriage

Hilchos Issurei Biah 12:8

Intermarriage causes a person to cling to the nations among whom we are exiled, and to turn away from following God.

Hilchos Issurei Biah 12:9

Let’s say that a non-Jewish man engages in sexual relations with a Jewish woman. If she’s married, he is subject to execution for adultery; if she’s unmarried, he isn’t executed.