Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
tabarani:19640ʿAbdullāh b. Muḥammad b. Saʿīd b. Abū Maryam > Muḥammad b. Yūsuf al-Firyābī > And Rqāʾ > Ibn Abū Najīḥ

[Machine] In his saying, "The good and the evil," he said, "It is the bad speech and the good speech. The good speech is for the believers and the bad speech is for the disbelievers."  

الطبراني:١٩٦٤٠حَدَّثَنَا عَبْدُ اللهِ بْنُ مُحَمَّدِ بْنِ سَعِيدِ بْنِ أَبِي مَرْيَمَ ثنا مُحَمَّدُ بْنُ يُوسُفَ الْفِرْيَابِيُّ ثنا وَرْقَاءُ عَنِ ابْنِ أَبِي نَجِيحٍ عَنْ مُجَاهِدٍ

فِي قَوْلِهِ {الطَّيِّبَاتُ} {وَالْخَبِيثَاتُ} قَالَ «هُوَ الْقَوْلُ السَّيِّءُ وَالْحَسَنُ فَالْقَوْلُ الْحَسَنُ لِلْمُؤْمِنِينَ وَالْقَوْلُ السَّيِّءُ لِلْكَافِرِينَ»