In Exodus 12:15, the Israelites were instructed to remove leaven from their home. The Hebrew word is שְׂאֹר, 'se-or', which was a small batch of leavened dough, that was used to leaven the next batch. Within this batch of dough, was controlled corruption, a process known scientifically as fermentation. What are these attitudes? What did Christ warn His disciples about relating to this leaven, and how does it impact us in the modern era today?