“A Retzitza (chick) that dies in its shell, through where does the spirit-of-life exit ?” He said to them, “Through where it entered” (Bekhorot 8b).

A chick — This is an eFRoaCh, the concept of tzaddik: “A tzaddik, like a date palm, yiFRaCh (will flourish)” (Psalms 92:13) ; and as in, “In his days, the tzaddik yiFRaCh” (Psalms 72:7).

[The Wise Men of Athens] asked him: The tzaddik who kills himself and sacrifices his soul in prayer and entreaties, in which place in the prayer does he especially have to sacrifice his soul?

And [Rabbi Yehoshua] answered them:

Through where it entered — Namely, wherever he has to elevate the sparks of holiness. In other words, wherever external thoughts enter into him he has to elevate them. This is because the external thoughts are actually the fallen sparks of holiness, and he has to elevate them, as is known. That is where he has to sacrifice his soul. A chick that dies - a chick that perishes inside its shell: