Shared ground
Deuteronomy 15:19–23 treats the firstborn males of cattle and sheep as belonging in a special way to Yahweh (explicit: they are to be “set apart”). That “set apart” status is explained through concrete limits: these animals are not to be used as ordinary economic assets (no field work for the firstborn ox; no shearing the firstborn sheep). The passage also ties this dedication to worship centered “in the place Yahweh will choose,” where the household eats the firstborn “before Yahweh” on a regular, repeating basis.
The text also makes clear that dedication does not cancel standards for what can be offered: a firstborn with a serious defect (examples: lame or blind) is not to be sacrificed. Yet it is not treated as untouchable; it may be eaten locally as ordinary meat, with the ongoing restriction that the blood must not be eaten.
Where interpretation differs
Some readers think “eat it before Yahweh” implies a more defined ritual pattern (for example, specific parts being given away while the rest becomes a worship meal), while others read the line more generally as “bring it to the central sanctuary and eat it there as a worship meal.” The passage itself highlights the meal and the location, but does not spell out detailed portioning.
There is also some uncertainty about timing: “year by year” can be read as a strict once-a-year requirement, or as an idiom for a recurring annual practice as firstborn animals become available.
Why the disagreement exists
The wording is brief and assumes background knowledge about sanctuary practice. It emphasizes the place, the household meal, and the acceptability rules, but leaves other details (like exact distribution of meat, or the precise calendar timing) unstated.
What this passage clearly contributes
It connects worship to household economics: honoring Yahweh involves relinquishing normal profit from the firstborn and turning that value into a shared worship meal at the chosen sanctuary (explicit). It also clarifies boundaries: firstborn status does not make a flawed animal acceptable for sacrifice (explicit), and “local eating” is allowed only when the animal is disqualified, with blood still prohibited (explicit; compare Deuteronomy 12:16). The passage therefore defines dedication, centralized worship practice, and the distinction between sacrifice versus ordinary eating in a tightly linked way.