Jewish self-confidence | מקורות

(12) The four species are likened to different categories in the Jewish people. (13)

The Etrog, which has both taste and smell, is likened to those that study Torah and do mitzvot.

14) The palm branch, which has taste, but no smell,

 is likened to those who have only Torah study. 

(15) The myrtle, which has smell but no taste,

is likened to those who have only mitzvot.

 (16) The willow, which has neither taste nor smell,

 is likened to those who are without Torah study and without mitzvot. 

(17) And Hashem says "bind them all together 

and let them atone one for the other."

לטקסט בעברית 

Vayikra Rabbah 30:12-17