Chametz of the Mind
"מצות יאכל את שבעת הימים ולא יראה לך חמץ ולא יראה לך שאור בכל גבולך"
Chazal explain that the pasuk means you are not allowed to see your own chametz but you can see the chametz of others.
Halacha isn't just dos and don'ts, there are moral/ethical lessons contained therein. What is the deeper message?
Chametz represents חימוץ המוח (spoilage of the mind), when our thoughts turn sour and our minds are occupied with bad thoughts. חמץ is unique because it is אסור במשהו. So too we need to purge our minds of "chametz" as well. How? Purging it, getting rid of it, and chasing it out. Once one purges one's mind of impure thoughts, if they come back, one is not חייב; one is only חייב if you don't get rid of them. "שלך אי אתה רואה אבל אתה רואה של אחרים" - if we don't take ownership of impure thoughts (by moving on) we are not liable for them. We are only responsible to get our mind in order.
Provided courtesy of rabbisilber.com