Why would dough be offered to God as firstfruits?

In Romans 11:16, Paul transitions to the famous image of a tree and its branches: If the root is holy, so are the branches (Romans 11:16b). He highlights that this not primarily about the branches, but rather about the tree of which they are a part. Paul will now discuss this in greater detail in Romans 11:17–24, but just prior to introducing this image Paul writes a somewhat mysterious sentence in Romans 11:16a, which reads as follows: If the dough offered as firstfruits is holy, so is the whole lump. Some translations render this as if a small part of the dough is devoted to God, the rest of the dough is too (see, e.g. NIV). If this translation were to be accepted as correct, it would mean that Paul is lying here. Devoting only a part of the harvest to God entails that the rest of the harvest remains undevoted to him and can be consumed and disposed of freely. It is not subject to any prohibitions or claims. This would of course also apply to the dough, even though it is doubtful that there was ever a portion of a lump of dough devoted to God.

The German theologian Matthias Hartung¹ highlights the Jewish rule (Chal. 3, 1) according to which people would be in sin if they ate dough from which the firstfruits had not been severed, because then there would be something holy in the dough (in other words, all of the dough is not holy). Cranfield². admits that the Jewish sources never support the idea that all dough would be holy because of the sacrifice of the firstfruits, but he also embraces Lagrange’s suggestion that this idea is conceivable with an appeal to Leviticus 19:23–25, which records the law that you may eat the fruit of a newly planted tree only after the fourth year. This law, however, actually only indicates that the fruit of the fourth year is holy and that one may eat the fruit from the fifth year on. It does not speak about the holiness of the later fruit. In contrast, in Romans 11:16, the dough is called holy. As such, the Romans 11:16 cannot refer to the entire harvest and to all the dough in Israel. Paul writes: If the dough offered as firstfruits (aparchai) is holy, then so is the whole lump, with the Greek word translated as firstfruits, aparche, literally meaning votive offering, first gift. The Greek translation of the Old Testament, however, uses a different word for the first yield of the harvest (the firstfruits), namely, protogennema. These firstfruits also functioned as a votive offering to God, even if not all votive offerings necessarily consisted of firstfruits of the harvest. In Romans 11:16 this therefore must be understood as the first gift of the grain harvest, hence the reference to dough. Dough produced by baking grain that was brought into the temple was not intended to be for everyday consumption. As the product of the first grains, it remains just as devoted to God as the first gift itself. Only the priests and the Levites were permitted to eat of it (Numbers 18:12–32). In other words, the consecration of the grain also determined the sanctity of the dough that had been produced from it. This helps us understand the connection between Romans 11:16a and Romans 11:16b: consecrated grain leads to consecrated dough, and a holy root leads to holy branches.³