A congregant told me that he was asked about T’shuvah (repentance) with his granddaughter. He was thinking about how to explain it to her when he cut himself shaving. He got a little blood on his shirt and neglected to clean the stain. He had let the stain slip his mind, and when he did try and cleain it, the stain left a permanent mark on his collar. He then that realized how he could explain T'shuvah.
Just like the stain on his collar, if we make a mistake in life we should take care of it right away, lest it leave a stain that will be with us forever.
We are reminded that we can cleanse ourselves, no matter how stain-soaked we have become.