To make the Heart Tender (Ar-Riqaq)
Ṣaḥīḥ al-Bukhārī 6551
مَا بَيْنَ مَنْكِبَىِ الْكَافِرِ مَسِيرَةُ ثَلاَثَةِ أَيَّامٍ لِلرَّاكِبِ الْمُسْرِعِ
mā bayna mankibāi al-kāfiri masīrah thalāthah ayyāmin lilrrākibi al-musriʿi
Transliteration generated from the Arabic vowel marks
The full narration
Narrated Abu Huraira: The Prophet (ﷺ) said, "The width between the two shoulders of a Kafir (disbeliever) will be equal to the distance covered by a fast rider in three days
Source
Ṣaḥīḥ al-Bukhārī · 6551
Ṣaḥīḥ