Midrash Rabbah - Leviticus 22:2
1 א
ויקרא רבה (וילנא) פרשה כב סימן ב
2ב
ורבנן אמרי ויתרון ארץ אפילו דברים שאתם רואים בעולם מיותרין כגון זבובין פרעושים ויתושים אף הן בכלל ברייתו של עולם דכתי' (בראשית ב) ויכולו השמים והארץ וכל צבאם
Our Rabbis explain the text, ’And the superfluities of the earth’ (Eccl. 5:8) as signifying that even things which seem to you superfluous in the world, such as flies, fleas, and gnats, are also included in the scheme of the creation of the world; as it is written, “And the heaven and the earth were finished, and all the host of them” (Gen. 2:1). [Soncino Translation]
3 ג

Suggested Discussion Questions:

Can you think of an example of something in creation that might be considered superfluous by some, but has an important purpose?

4 ד
Time Period: Rabbinic (Maccabees through the Talmud)