Tirukkural-On Virtue-Not Coveting Another's Wife-Kural 146

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Enmity, sin, fear and shame will never leave those, who lust after the neighbour's wife.

These four unhappy developments are always the concomitants of the adulterous behaviour of a man, who crosses the bounds of decency in his dealings with his neighbour's wife.

A parallel expression is found in Naladiar thus:

.pinranthaaram

Nachchuvaarchaerum pahaipalipaavam yenru
Achchath thoadinaar porul