தி‌யினால் சுட்ட புண் உல் ஆறும் அராதே நாவினால் சுட்ட வடு.

தி‌யினால் சுட்ட புண் உல் ஆறும்  அராதே நாவினால் சுட்ட வடு.

Meaning, the wounds caused by burns or fire heals Whereas the wounds caused by words don't heal.

In a different context this can also be interpreted or reanalyzed from a different perspective,

That is, the wound caused by burns or fire always leave a scar or mark in your body that reminds you of the pain for your life time and many of them hide their Scar with clothes to hide the scars from others.  Whereas there is no Visible marks or scars left by words and human being or people move on with their life from those harsh words even though it caused a deep hurt in their heart, emotion and thinking.

So, from this perspective this gives exactly opposite meaning.  However, both are pain and leaves a Mark visible or invisible mark.  The sloka says that the wound caused by harsh words leaves a deeper impact but that depends on time, the sayer, the hearer, the Context, the event, the Situation, the words used, the impact or impression left on the heater and their respective state of  mind.