Tirukkural-On Virtue-On Rectitude-Kural 119

Corkoattam illadhu seppam oruthalaiya
Utkoattam inmai perin.

Here is a translation based on K Srinivasav's

If the mind is free from bias,The words uttered are bound to be fair.

If the inner rectitude of mind is present the outer manifestation of it in words will follow. The idea is that true rectitude is based more on thought than on words, which are however important too. Valluvar, as the perfectionist in virtue who has said,

Manathukkan maasilan aadhal anaithiran
Aaakula neera pira

(Kural 34)

attaches greater meaning to the inner content of rectitude. Even so, the words are what affect others. The existence of great men who speak straight and fair, is what Illangovadigal refers to as one of the glories of 'Puhar'.

Nadukinri nilai iya yenpathalladhu
Odukkam kooraar uyarnthoar unmaiyaal

(Silapathikaaram-Mangala Vaalthu)