(Lev. 23:40) And you shall take for yourselves, on the first day, the fruit of a ‘hadar’ tree, date palm fronds... etc. – the ‘citron’ (etrog) is the Lower Shekhinah, and it is like the heart,lxxxviVayiqra Rabbah 30:14 which is to the left, which is Gevurah.
And therefore, a person should take the etrog (citron) in the left hand. And it needs to be an etrog that is like the heart, complete, with its ‘tyomet’ because of him of whom is stated: (Gen. 25:27)... and Jacob was a complete (tam) man – to be perfect with Him. And just as there is no defect in Jacob above, so there must be no defect in the etrog, to fulfill the verse: (Song. 4:7) You are completely beautiful my beloved, there is no blemish in you.