Question

The passage in Menachot beginning on 7b discusses which Jewish laws can be derived from which other laws. The question there is whether from a certain law regarding blood—that it is not consecrated in part, meaning that if one received in the vessel less blood than the amount required for the sprinklings, the blood is not consecrated—one may also derive that in the case of a meal-offering that requires a certain measure, the required measure may not be brought in parts. For example, the High Priest’s griddle-cake offering is one tenth of an ephah, half of which is offered in the morning and half in the afternoon. Can one bring half a tenth for the morning offering and half a tenth for the afternoon offering, or must one bring the meal-offering whole and only afterward divide it in half? The Talmud discusses whether one may derive from blood that just as blood is not consecrated in halves, so too a meal-offering is not consecrated in halves, and the discussion is framed around whether one may derive one matter from another; that is the continuation of the whole passage there.
From what I have seen, this seems to be a unique passage in the Talmud that discusses whether one may derive one matter from another. Elsewhere in the Talmud, as far as I know, one derives one topic from another with almost no hesitation. For example, Mishnah Menachot, chapter 12, mishnah 5:
“One may vow wine, but one may not vow oil”—these are the words of Rabbi Akiva. Rabbi Tarfon says: “One may vow oil.” Rabbi Tarfon said: “What do we find with regard to wine? It comes both as an obligatory offering and as a voluntary offering; so too oil comes both as an obligatory offering and as a voluntary offering.”
Or the passage in the Babylonian Talmud, Sotah 16b:
“So that it will be visible on the water.” The Sages taught: There are three things that must be visible: the dust used for the sotah, the ashes of the red heifer, and the saliva of a yevamah.
And the Talmud derives the dust of the sotah from the ashes of the red heifer.
And perhaps also in Bava Kamma 17b:
Rava said: “Anything that in the case of a zav is impure—in damages one pays full damages; anything that in the case of a zav is pure—in damages one pays half damages.” And did Rava come to teach us the law of pebbles kicked up indirectly? No, Rava came to teach us the case of a wagon pulled by oxen.
And it seems that the laws of damages are being derived from the laws of impurity and purity.
And perhaps also connected to this topic is the rule: since something counts as a partition with regard to the Sabbath, it also counts as a partition with regard to a sukkah.
The passage in Menachot seems exceptional—what is the explanation there?