Ruth 4:19
Hezron was the father of Ram,
What it says
Perez's line continues through Hezron and Ram.
What it is doing
It begins the chain of descent.
In context
18Now these are the generations of Perez: 19Hezron was the father of Ram, 20Amminadab was the father of Nahshon, 21Salmon was the father of Boaz, 22Obed was the father of Jesse,