Abdullah bin Masud reported,

A servant keeps on lying, and with each lie a black spot is marked upon his heart, until his whole heart turns black, and then he is recorded with Allah among the liars.

أن

عبد الله بن مسعود كان يقول

لا يزال العبد يكذب، وينكت في قلبه نكتة سوداء، حتى يسود قلبه كله، فيكتب عند الله من الكاذبين.