It is narrated from Sayyiduna Bilal bin Harith that the Prophet (peace and blessings be upon him) said: Sometimes a person utters a word seeking Allah’s pleasure, not realizing its significance, but because of it Allah writes for him His pleasure until the Day of Resurrection. And sometimes a person utters a word that angers Allah, not realizing its gravity, but because of it Allah writes for him His displeasure until the Day of Resurrection. The narrator of the hadith, Alqamah, says: There are many things which I refrain from saying because of this hadith of Sayyiduna Bilal.
Hadith Referenceمسند احمد / مسند المكيين / 15852
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف لجهالة عمرو بن علقمة