Abu Hurairah (May Allah be pleased with him) reported: I heard the Prophet (ﷺ) saying, “A person utters a word thoughtlessly (i.e., without thinking about its being good or not) and, as a result of this, he will fall down into the fire of Hell deeper than the distance between the east and the west.” [Al-Bukhari and Muslim].
“Indeed, those for whom the best [reward] has preceded from Us – they are from it far removed.They will not hear its sound, while they are, in that which their souls desire, abiding eternally…” more: quran.com
The Messenger of Allah, peace and blessings be upon him, said, “Verily, truthfulness leads to righteousness and righteousness leads to Paradise. A man may speak the truth until he is recorded with Allah as truthful. Verily, falsehood leads to wickedness and wickedness leads to the Hellfire. A man may tell lies until he is recorded with Allah as a liar.” Source: Sahih Muslim 2607