In an attempt to identify Ruth in terms of other biblical figures, the Talmud claims that she was the daughter of the Moabite king Eglon[?], who figured briefly in the Book of Judges. This can also be seen as an attempt to provide a royal lineage to David. There is, however, no basis in the actual verses for such an assertion.
This story is told in the Book of Ruth, a part of the Tanakh (Hebrew Bible) and the Christian Old Testament.
wikipedia.org dumped 2003-03-17 with terodump