Salmon begat Boaz - Matthew has preserved the additional interesting information that the mother of Boaz was Rahab Joshua 2; Joshua 6. It is possible that the circumstance that the mother of Boaz was a Canaanite may have made him less indisposed to marry Ruth the Moabitess. As regards the whole genealogy in Ruth 4:18-22, it should be remarked that it occurs four times in Scripture, namely, here, 1 Chronicles 2:10-12; Matthew 1:3-6; and Luke 3:32-33, and is of course of singular importance as being the genealogy of our Lord. One or two difficulties in it still remain unsolved.
Related Commentaries of Ruth 4:21
Ruth 4:21
21 And Salmon begat Boaz, and Boaz begat Obed,