Looking at the words Ephrathite and Ephraimite (אפרתי) they have the exact same spelling. From the website doitinhebrew.com the dictionary even said: ‘Ephraimite; inhabitant of Ephrat(ah).’
This reminded me of Beit Lechem the homeground or ancestral home of both Elimelech and Naomi, who are called Ephratites in the book of Ruth (1:2). Which could be derived from the fact that Boaz is identified as a member of Elimelech his family (1:2), a near kinsmen redeemer for Naomi (2:2, 3:12), and a direct descandant of Yehudah (4:18-20). Boaz also identifies Elimelech as ‘a brother’ when he speaks with the nearest kinsmen redeemer (4:3).
So here’s the thing: we know that because of a famine they have to leave Beit Lechem and that when Elimelech and the two sons of Naomi have passed away that she returns with her daughter-in-law Ruth. From the story it becomes clear that Naomi, an Ephraimite, owned ancestral land in Beit Lechem which she decided to sell in an attempt to secure a life partner for Ruth in the hope of raising up a son in the name of Ruth’s widow and Naomi’s deceased son, Mahlon. Because Naomi’s son Mahlon was the rightful heir to her ancestral land, Mahlon’s widow, Ruth, came with the land and the man who purchased the land would be required to fulfill the levirate marriage rites and raise up a son to Mahlon, which would become the heir of the land.
Well, Boaz was that man, and he and Ruth got married, Ruth gave birth to Obed, the father of Yishai, who became the father of David HaMelech. Obed is said to be the grandson of Naomi (for clear reasons), and Ruth would be the great-grand-mother of David.
So David could be seen as a Ephratite of Beit Lechem Yehudah.
If Elimelech and Naomi hadn’t had an ancestral right to the land in Beit Lechem, Boaz wouldn’t had the responsibility to fulfill the levirate marriage role with Ruth because the land was the rightful inheritance of Mahlon.
The fact that Ephrat(ah) isn’t listed as one of the cities of Yehudah, coupled with the fact Elimelech and Naomi are called Ephratites, which could mean the same as Ephraimites, and their ancestral right to land in Beit-Lechem, it may be concluded that this city in the territory of Yehudah was quite different from all other cities in this area. Why? Because it could be that many people in this city had ancestral ties to two tribes, Ephraim and Yehudah.
Because Boaz is a member of Elimelech’s family, could it be he’s also a Ephraimite living in Yehudah?! Of course Boaz is also from the lineage of Yehudah as stated in the end of the book of Ruth.
So here’s my question: could it be that David is descended from both Ephraim as well as Yehudah?