I figured out yesterday's reading. I opened my NAB Bible today, and decided to look for that verse. But when I opened the bible, it opened to Luke instead of Mark, but it was on the exact page as the Luke version of the story. Basically, the leavens referred to in the reading is the hypocracy of the Pharasees. I still haven't figured out the second half of the reading yet. I'll do a little more research tonight.