A mixed marriage is when a Jewish person marries a non-Jewish person (a gentile). God gave specific instructions about these marriages. God forbade the Israelites from marrying the original people who lived in Canaan. This rule existed because God was concerned that Israelites might start worshiping idols instead of him (Deuteronomy 7:1–5). The New Testament also warns believers not to be "unequally yoked" with unbelievers (2 Corinthians 6:14).
Despite this rule, many Israelites did marry foreigners during the time of the judges (Judges 3:6). This also happened later (2 Samuel 11:3; 1 Kings 11:1–8).
God gave no clear prohibition against marriages with other nationalities (Numbers 12:1; Deuteronomy 23:7; Ruth 1:4). After the Jewish people returned from exile in Babylon, the leaders Ezra and Nehemiah strongly opposed marriages between Jews and non-Jews (Ezra 9:1–4; Nehemiah 13:23–27).