Tirukkural-On Virtue-Avoiding Slander-Kural 181

A man may speak and do evil, but if it is said Of him that he does not slander, it is great.

To speak ill of others, particularly behind their back is the vice that is here enjoined, as the thing to be firmly eschewed on a priority basis, being worse than all other sins. The idea is to emphasise the grievousness of the sin of slander.

The following lines in Naladiar contain the same precept:

Purankooraan muhaiyaal nirpaan yaadhum
Arangoorum aakan tharum

The Biblical parallel is recorded below:-

'Who so privily slandereth his neighbour; him will
I cut off; him that hath an high look and a proud

Heart will not I suffer'.

(Psalms 101:5)