The Peak of Eloquence · Hadith 821 (#Passage #11)
Chapter 176 | Greatness of the Quran, following the Sunnah and refraining from innovation
وَلَقَدْ قَالَ رَسُولُ اللهِ (صلى الله عليه وآله): «لاَ يَسْتَقِيمُ إيمَانُ عَبْد حَتَّى يَسْتَقِيمَ قَلْبُهُ، وَلاَ يَسْتَقِيمُ قَلْبُهُ حَتَّى يَسْتَقِيمَ لِسَانُهُ»؛ فَمَنِ اسْتَطَاعَ مِنْكُمْ أَنْ يَلْقَى اللهَ سُبْحانَهُ وَهُوَ نَقِيُّ الرَّاحَةِ مِنْ دِمَاءِ الْمُسْلِمِينَ وَأَمْوَالِهِمْ، سَلِيمُ اللِّسَانِ مِنْ أَعْرَاضِهِمْ، فَلْيَفْعَلْ.
The Prophet of Allāh — peace and blessing of Allāh be upon him and his descendants — said: “The belief of a person cannot be firm unless his heart is firm, and his heart cannot be firm unless his tongue is firm.” So whoever of you can manage to meet Allāh, the Sublime, in such a position that his hands are unsmeared with the blood of Muslims and their property and his tongue is safe from exposing them, he should do so.
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).