Kural - 716

As in the way one tottering falls, is slip before
The men whose minds are filled with varied lore

Explanation
(For a minister) to blunder in the presence of those who have acquired a vast store of learning and know (the value thereof) is like a good man stumbling (and falling away) from the path (of virtue).

Tamil Transliteration
Aatrin Nilaidhalarn Thatre Viyanpulam
Etrunarvaar Munnar Izhukku.