Ruth 4

 It becomes apparent that Boaz was a righteous man obedient to the law of Moses.  We also learn that he was a descendant of Pharaz and Judah - 

"...let thy house be like the house of Pharez, whom Tamar bare unto Judah, of the seed which the Lord shall give thee of this young woman."  (Ruth 4:12)

...of whom David was a descendant of Boaz and Ruth, and then later Mary, the mother of Jesus Christ.