Shared ground
Jeremiah 16:19–21 combines a personal address to Yahweh (“my strength…stronghold…refuge”) with a widened horizon: “nations” come from far away and admit that what they received from their “fathers” was false and empty. The passage assumes that inherited religion can be wrong, even when it is deeply traditional.
The nations’ confession is sharpened by a pointed question: humans can manufacture “gods,” but what they make cannot be truly divine. The text’s basic contrast is between Yahweh’s real power (“hand” and “might”) and the unreality of made gods.
Finally, Yahweh speaks: he will make “them” know his power, so they know his name is Yahweh. Knowledge here is not abstract information; it is recognition produced by what Yahweh does in history.
Where interpretation differs (only where needed)
Who is the “my” speaker in v.19? Some read the “my strength…my refuge” voice as Jeremiah personally. Others see Jeremiah voicing Israel/Judah (or a representative worshiper) in a way that can stand for the community.
Who are “them” in v.21? Many read “them” as the same “nations” who come and confess in v.19, so Yahweh’s self-disclosure is directed outward to the nations. Others think “them” may include Judah too (or even primarily Judah), since the chapter’s wider setting is Judah’s coming judgment and the questions people will ask about it.
What does “this once” mean? Some take it as a single decisive intervention (a particular act that forces recognition). Others take it more broadly as a decisive season of unmistakable action.
Why the disagreement exists
The passage shifts quickly from first-person prayer (“my…”) to the speech of “nations,” then to Yahweh’s own declaration. Because pronouns and speakers move fast, readers differ on whether v.21 continues the nations-focus of v.19 or returns to Judah’s situation in the chapter.
What this passage clearly contributes
Explicitly, it states that nations will come, confess inherited falsehood, and be confronted with the absurdity of human-made gods. It also states that Yahweh will act so that “they” know his power and recognize his specific name, Yahweh (yahweh). Theological inference that fits these claims is that Yahweh’s identity is meant to be publicly knowable beyond Israel, and that his self-revelation is tied to concrete acts of power, not merely to inherited tradition.