Ruth 1:4
"And they took them wives of the women of Moab; the name of the one was Orpah, and the name of the other Ruth: and they dwelled there about ten years."
Cross References (ranked by relevance)
Matthew 1:5
And Salmon begat Booz of Rachab; and Booz begat Obed of Ruth; and Obed begat Jesse;
Deuteronomy 23:3
An Ammonite or Moabite shall not enter into the congregation of the LORD; even to their tenth generation shall they not enter into the congregation of the LORD for ever:
Deuteronomy 7:3
Neither shalt thou make marriages with them; thy daughter thou shalt not give unto his son, nor his daughter shalt thou take unto thy son.