'Bowels' in the Bible

And, behold, the word of Jehovah came unto him, saying, This man shall not be thine heir; But he that shall come forth out of thine own bowels shall be thine heir.

And Jehovah said unto her, Two nations are in thy womb, And two peoples shall be separated from thy bowels. And the one people shall be stronger than the other people. And the elder shall serve the younger.