What is pure? Which is rich only it’s said content with proper amount, you can call it pure.
Suppose, pure water, pure hygiene, pure silk, pure milk,etc. etc.
Often we search for pure heart which is only available with innocent people. When the people act without thinking for himself, his serving is pure.
If a person falls on the road or somebody is critical we have seen that the public rush towards him and do the needful. Innocence is everywhere.
In a local cricket match, the children or the grown boys try to get runs and wickets at any cost, i.e. purity.
When anybody body hurts you, whom you have loved and you cry in despair is purity.There your heart bleeds and weeps. To get back to your normal state forgetting it- it is purity.
We all have pure hearts and we know the right and wrong in us.