For the source text click/tap here: Pesachim 7
To download, click/tap here: PDF
The Arizal himself had a custom to scatter ten pieces of bread before his search. Some poskim explain that the reason for this practice is so that some ĥametz will remain after the search, and thus one will not forget to nullify his ĥametz. [1]
I have suggested that the 10 pieces of bread represent the 10 dark sides of the sefirot that are hidden behind our facades of light. “there is no light without darkness” the Zohar tells us. Since leaven represents the “ferment of base desires” the search for these 10 crumbs dramatizes the need to look in the hidden places of our inner psychic homes to expose by the candle/light of the soul, before the drama of the Seder and the deliverance.
And he searched, beginning with the oldest, [so that they not suspect him of knowing where it was], and finishing with the youngest, and the goblet was found in Benjamin's sack.
Gen 44:12
He replied “we have here brothers who sold their own brother” meaning “who are you to talk about thievery!
For the Zohar and the ARI z’l, the betrayal and sale of Joseph becomes a recurring theme throughout Jewish history and the cause of the (protracted) exile.
I think the use of this prooftext about Benjamin reflects the deeper notion that each Pesach we search for the 10 crumbs, we search for the “ferment of base desires” the leavening of ego and self promotion, in fact we are searching for the soul of the brothers, to fix the ongoing betrayal of self and others in the pursuit of ego and its desires.