Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "A man may say something by which he intends no evil, only that people may laugh at it, yet because of it he falls (into Hell) from a height farther than the sky."
Al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains Atiyyah al-Awfi, whom Yahya bin Ma'in declared thiqah (trustworthy), and he is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 13105