Shared ground
This short paragraph is a family record: it completes the list of David’s sons born in Jerusalem by naming them and giving a total. It highlights four sons tied specifically to Bath-shua and identifies her by her father’s name (Ammiel), treating her as an important link in the record.
The text also shows that genealogies can be selective and layered. Even after listing nine Jerusalem-born sons, it adds that David had other sons through concubines, and it mentions Tamar as their sister. So the writer is not trying to give a complete “all children everywhere” list in one sweep; it is finishing one segment of a larger household record.
Where interpretation differs
Two issues are read differently.
First, the repeated names (Elishama and Eliphelet) can be taken as two different sons who happened to share the same name, or as a copying/listing problem that duplicated a name.
Second, the word “nine” can be read as “nine entries in the list as presented” or “nine distinct sons,” depending on what someone thinks is happening with the repeated names.
Why the disagreement exists
The passage is a compact list, not a narrative explanation. It gives no extra notes like “the younger” or “another,” so the reader has to infer why two names occur twice. Also, other biblical lists of David’s children do not match every spelling or detail exactly, which raises the possibility of textual variation or alternate name-forms. These features create room for different, reasonable reconstructions while the main point of the list remains clear.
What this passage clearly contributes
Explicitly, it anchors David’s royal household in Jerusalem and preserves the names and relationships that mattered for later royal descent records. It also makes clear that (1) four Jerusalem sons are linked to Bath-shua, (2) the Jerusalem list is counted as nine, (3) the list is not exhaustive because of sons by concubines, and (4) Tamar is remembered as a sister within this family frame. Those points support Chronicles’ broader interest in tracing David’s line and organizing Israel’s remembered ancestry (1 Chronicles 3:1).