Musnad Ahmad 26:91

Abu Mu'awiyah narrated to us, Al-A'mash narrated to us, from Shaqiq, from Abdullah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "You must be truthful, for truthfulness leads to righteousness, and righteousness leads to Paradise. A man continues to be truthful and strives for truthfulness until he is recorded with Allah, the Almighty and Majestic, as a truthful one (Siddiq). And beware of lying, for lying leads to wickedness (fujur), and wickedness leads to the Fire. A man continues to lie and strives for lying until he is recorded with Allah as a liar."