4 And they took wives for themselves from the women of Moab. The name of the one was Orpah, and the name of the other Ruth. And they lived there about ten years.
Ruth 1:4 Cross References - MKJV
Deuteronomy 7:3
3 Nor shall you make marriages with them. You shall not give your daughter to his son, nor shall you take his daughter to your son.
Deuteronomy 23:3
3 An Ammonite or Moabite shall not enter into the congregation of Jehovah. Even to their tenth generation they shall not enter into the congregation of Jehovah forever,
1 Kings 11:1-2
1 And King Solomon loved many foreign women, even the daughter of Pharaoh, Moabites, Ammonites, Edomites, Sidonians, Hittites;
2 of the nations which Jehovah had said to the sons of Israel, You shall not go in to them, and they shall not go in to you; surely they will turn away your heart after their gods. Solomon clung to these in love.
Matthew 1:5
5 And Salmon fathered Boaz of Rahab, and Boaz fathered Obed of Ruth, and Obed fathered Jesse,