TABARANI 1136:
from Bilāl b. al-Ḥārith —
[Machine] I heard the Messenger of Allah ﷺ saying, "Indeed, a person speaks a word of goodness without realizing its significance, and Allah writes for him His pleasure with it until the day he meets Him. And indeed, a person speaks a word of evil without realizing its significance, and Allah writes against him with it His displeasure until the day he meets Him."
الطبراني ١١٣٦:
عن بلال بن الحارث —
سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ «إِنَّ الرَّجُلَ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنَ الْخَيْرِ مَا يَعْلَمُ مَبْلَغَهَا يَكْتُبُ اللهُ لَهُ بِهَا رِضْوَانَهُ إِلَى يَوْمِ يَلْقَاهُ وَإِنَّ الرَّجُلَ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنَ الشَّرِّ مَا يَعْلَمُ مَبْلَغَهَا يَكْتُبُ اللهُ عَلَيْهِ بِهَا سَخَطَهُ إِلَى يَوْمِ يَلْقَاهُ»