Abu Huraira reported: The Prophet, peace and belssings be upon him, said, “Verily, a servant may speak a word pleasing to Allah, thinking nothing of it, yet by it Allah raises his status by a degree. Verily, a servant may speak a word displeasing to Allah, thinking nothing of it, yet by it he plummets into Hell.”
Source: Ṣaḥīḥ al-Bukhārī 6113
Grade: Sahih (authentic) according to Al-Bukhari
عَنْ أَبِي هُرَيْرَةَ عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِنَّ الْعَبْدَ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنْ رِضْوَانِ اللَّهِ لَا يُلْقِي لَهَا بَالًا يَرْفَعُهُ اللَّهُ بِهَا دَرَجَاتٍ وَإِنَّ الْعَبْدَ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنْ سَخَطِ اللَّهِ لَا يُلْقِي لَهَا بَالًا يَهْوِي بِهَا فِي جَهَنَّمَ
6113 صحيح البخاري كتاب الرقاق باب حفظ اللسان