ויקרא פרק ב, יא כָל-הַמִנְחָה אֲשֶׁׁר תַקְרִ יבוּ לַה' לֹא תֵעָשֶׁה חָמֵץ כִי כָל -שְאֹר וְכָל -דְ בַשׁ לֹא -תַקְ טִירוּ מִמֶׁנּוּ אִשֶׁה לה'
The Torah does not explain the prohibition against offering leavening or honey on Korbanos.
Rabbi Epstein explains that leavening symbolizes the concept of the Yetzer HaRa, an agent that causes an increased ego in a person. Just like leavening causes bread to raise, so does the Yetzer seeks to inflate a person’s view of themselves. One would think of oneself as a "כל שהו" , which would lead one to the mistaken notion that one is important and separate from G-d, which is the exact opposite of the goal of a korban.
Regarding the prohibition to put honey on the korban, one could say that some types of honey seemingly derive from an impure source (bees). Even though honey is not assur for non-sacred uses since the body of the bees does not assist in the development of the honey, nevertheless, it is not appropriate to use on the holy Korban. Therefore, since the verse says “all” honey, one also does not use any honey even from dates.
Similarly one could support the understanding that one does not use milk products in the meal offerings. Milk is also a permitted item for non-scared uses that derives from a non-kosher source (evidently a derivative of blood). Thus, one does not use milk within the holy items in the Mishkan.
Now is a proper place to review why one does not offer types of fish in the Mishkan. The reason is not that fish are not an honored item, since we do use fish as an honored food on Shabbos. Further, fish were not included in the sins of the generation of the Flood. Plus, salt (a derivative of the sea) is used in the Mishkan.
Perhaps, one can understand about fish based on the Medrash that G-d said to the Jews, “10 types of animals (בהמות) I gave to you.” Three are within your domain (that they are domesticated), cows, sheep and goats. Seven types of animals are not under your control, but are first required to be captured. Therefore, G-d does not require the Jews to take the extra burden of capturing these animals to be offered in the Mishkan. And, fish which are always in need of capture, and thus, not in our control, G-d also does not burden us to bring fish as a korban.
