Toothbrushes and cleaning of teeth... the links today as possibly the most tenuous yet, with references to OT commandments limiting retribution, NT challenges to those by Jesus, 'you have heard it ssid... but I say...' and mentions of 'gnashing of teeth'

The message seems to be, brushing teeth is sensible and has health benefits, not doing so has consequences that can be painful and extreme, ergo brush your teeth.  Choices have consequences, so be careful what you choose.

Much more interesting was the social history - seemingly 'toothpaste' predates 'toothbrushes' and the Romans even has a law prohibiting the removal of gold teeth/repairs from corpses!

Law-giving God, sometimes your laws are bewildering, time and culture bound, and sometimes they are eternally true.  Help me to work out which are which, to evaluate the implications of those decisions, and to live wisely and well. Amen