Kingdom of heaven is like leaven that a woman took and hid meal until it was all leavened
Leaven typically represents sin in the bible. I am guessing this refers to how fast sin can expand in the kingdom? Some people may interpret it to refer to how quick God's kingdom can expand...
I'm not sure.
But personal application:
Be ware of how quick sin can expand in His kingdom. Be watchful of things that are not of truth and be diligent to guard my home from leaven.
I have seen this happen in our family. And it's hard to get leaven out once it has been in our home. I have been spending the last few months sorting out truth vs what was falsehoods that I had blindly taken as truth to keep the peace. I so wish I had been more clear on things in the beginning but now God is taking me through a time to sort out all the leaven and replace it with truth. It takes time but is well worth it.