Sayyiduna Mu'awiyah bin Abi Sufyan (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "Hold (firmly) to truthfulness! For it guides to righteousness, and the two of them (that is, truthfulness and righteousness) will be in Paradise. And it is binding upon you to beware of lying! For it guides to sins, and the two of them (that is, lying and sin) will be in Hell."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its chain is hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الإيمان / 332