If the Sudra intentionally listens for committing to memory the Veda ,

then his ears should be filled with molten lead and lac.

if the Sudra overheard the Veda or ventured to utter a word from the Veda, the king shall cut his  tongue in twain. If he has mastered the Veda, his body should be cut to pieces..

( from Manusmriti, Chapter 3,  Shloka 4 )