Kural - 560

Where guardian guardeth not, udder of kine grows dry,
And Brahmans' sacred lore will all forgotten lie

Explanation
If the guardian (of the country) neglects to guard it, the produce of the cows will fail, and the men of six duties viz, the Brahmins will forget the vedas.

Tamil Transliteration
Aapayan Kundrum Arudhozhilor Noolmarappar
Kaavalan Kaavaan Enin.