Mishkat al-Masabih 9 Supplications كتاب الدعوات 51

وَعَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَا تُكْثِرُوا الْكَلَامَ بِغَيْرِ ذِكْرِ اللَّهِ فَإِنَّ كَثْرَةَ الْكَلَامِ بِغَيْرِ ذِكْرِ اللَّهِ قَسْوَةٌ لِلْقَلْبِ وَإِنَّ أَبْعَدَ النَّاسِ مِنَ اللَّهِ الْقَلْبُ الْقَاسِي» . رَوَاهُ التِّرْمِذِيّ

Ibn ‘Umar reported God’s messenger as saying, “Do not speak much without mentioning God, for much talk without mention of God produces hardness of heart, and the one who is farthest from God is he who has a hard heart.” Tirmidhi transmitted it.