Sahih Muslim Book 32, Hadith Number 6308.

Chapter : The evil of a lie and the goodness of truth and its merit.

‘Abdullah b. Mas’ud reported Allah’s Messenger (may peace be upon him) as saying: Telling of truth is a virtue and virtue leads to Paradise and the servant who endeavours to tell the truth is recorded as truthful, and lie is obscenity and obscenity leads to Hell-Fire, and the servant who endeavours to tell a lie is recorded as a liar. Ibn Abu Shaiba reported this from Allah’s Apostle (may peace be upon him).