The Messenger of Allah ﷺ said, "Truthfulness leads to righteousness, and righteousness leads to Paradise. A man continues to speak the truth until he is recorded with Allah as a truthful one. Lying leads to wickedness, and wickedness leads to the Fire. A man continues to lie until he is recorded as a liar."In another wording, "Hold fast to truthfulness, for truthfulness leads to righteousness, and righteousness leads to Paradise. A man continues to speak the truth and strive for truthfulness until he is recorded with Allah as a truthful one. Beware of lying, for lying leads to wickedness, and wickedness leads to the Fire. A man continues to lie and pursue falsehood until he is recorded with Allah as a liar."
قال رسول الله ﷺ: إن الصدق يهدي إلى البر، وإن البر يهدي إلى الجنة، وإن الرجل ليصدق حتى يكتب صديقا، وإن الكذب يهدي إلى الفجور، وإن الفجور يهدي إلى النار، وإن الرجل ليكذب حتى يكتب كذابا. وفي لفظ: عليكم بالصدق، فإن الصدق يهدي إلى البر، وإن البر يهدي إلى الجنة، وما يزال الرجل يصدق ويتحرى الصدق حتى يكتب عند الله صديقا، وإياكم والكذب، فإن الكذب يهدي إلى الفجور، وإن الفجور يهدي إلى النار، وما يزال الرجل يكذب ويتحرى الكذب حتى يكتب عند الله كذابا.
Bukhari narrated it in al-Adab (6094), and Muslim in al-Birr wal-Silah (2607: 3/10), both of them through routes from Jareer, from Mansur, from Abu Waail (that is, Shaqiq bin Salama), from Abdullah, who related it with the first wording. Muslim also narrated it (2607: 105) through routes from Amash, from Shaqiq, from Abdullah, who related it with the second wording.