My main question was about the possibility that the things that were created are not aggadah; and since there is certainly room to say that they are in the category of aggadah, even though I have not looked into it deeply, your answer completely satisfied me. Much appreciated.

And also, whether it is reasonable to say that there is a point in time between day and night—it seems less reasonable to me. (And on that you answered that there is no such time; again, I have not checked what the common view is.)
And for that as well, my thanks to you.

Shabbat shalom.
Tam.

Perhaps there is room to explain that the ten things are not in the category of homiletics, and still this is no question.

In my opinion, one could say that their creation at twilight was in potential and not in actuality, and therefore there is no deficiency in the Sabbath rest because of it.

I would be glad to hear the Rabbi’s opinion: is there any Sabbath prohibition with creation in potential? (Even though Sabbath prohibition depends on intentional creative labor, in the end no labor was actually done. I mean this as a possibility, even if in the Rabbi’s view there is no such thing as creation in potential.)
Much appreciated.

There is no Sabbath prohibition, neither regarding creation in potential nor creation in actuality. The Holy One, blessed be He, is not bound by the prohibitions of the Sabbath. And even if He created something on the Sabbath itself, that would not contradict anything. In principle, He rested on the Sabbath, and in commemoration of that we observe the Sabbath every week. That does not mean He could not create a few things at twilight, and perhaps even on the Sabbath itself. In any case, human beings cannot create ex nihilo; they can only form something from something else, and therefore the prohibitions of the Sabbath do not relate to creation at all. This is a commemoration of the act of creation, not an exact imitation. Even the prohibited labors are not learned from creation but from the Tabernacle work (if at all).

Much appreciated, Rabbi.

I certainly did not mean that the Holy One, blessed be He, violated Sabbath labor, but rather that we learn that on the Sabbath He rested, and therefore it is not reasonable that He created on the Sabbath. And if we say that the ten things are a creation (in lomdus, even if only in potential), then there is proof that twilight is definitely day and not night.

Thank you very much.

From there there is actually proof against you, Tam. The whole nature of the ten things is that they are not such fully concrete creations [like the mouth of the donkey, the mouth of the earth; some say destructive forces]. It is certainly possible that they were created then, insofar as the mind can grasp what it means for such things to exist. And see the beginning of Tractate Pesachim, where it seems that twilight is a real doubt “from Heaven’s perspective,” and it is a point in time about which there are grounds to say it is day and grounds to say it is night, with no conceptual way to decide. Even if the meaning is not that they were actually created at twilight, the very statement apparently shows the Mishnah’s view that it is a “real doubt.”
And the Jerusalem Talmud innovated that if a child was born at twilight, his circumcision should be done at twilight after eight days. You can see that it holds that this is “evening”; I did not understand exactly what its view is.