Islam places great importance on the tongue, commanding believers to speak with kindness and avoid harmful speech. Words have the power to heal or hurt, to bring people closer to Allah or drive them away.
Allah says in the Qur'an:
وَقُولُوا لِلنَّاسِ حُسْنًا
"And speak to people good [words]."
— Surah Al-Baqarah (2:83)
The Prophet Muhammad ﷺ said:
"مَنْ كَانَ يُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الْآخِرِ فَلْيَقُلْ خَيْرًا أَوْ لِيَصْمُتْ"
"Whoever believes in Allah and the Last Day should speak good or remain silent."
— Sahih al-Bukhari (6136), Sahih Muslim (47)
The Sahaba were extremely cautious with their speech. Abu Bakr As-Siddiq (RA) was once seen holding his tongue and saying, "This has brought me to ruin," fearing speaking in error.
Backbiting, slander, shouting, or mockery are all forbidden. Allah warns:
يَا أَيُّهَا الَّذِينَ آمَنُوا لَا يَسْخَرْ قَوْمٌ مِّن قَوْمٍ
"O you who believe, let not a people ridicule another people..."
— Surah Al-Hujurat (49:11)
Speaking kindly reflects iman (faith) and brings people together. The best Muslims are those whose speech is gentle, wise, and beneficial.