Tirukkural-On Virtue-Pleasing Speech Or Courtesy-Kural 95

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Humility and pleasant speech constitute one's ornaments;
Other things do not count.

The best ornament of a virtuous man is the genuinely humble and pleasing speech.

Valluvar was obviously a genuine public relations man. These instructions are almost on the lines of the modern guidelines given by Dale Carnegie, in 'How to win friends and influence people.'