To make the Heart Tender (Ar-Riqaq)
Ṣaḥīḥ al-Bukhārī 6581
بَيْنَمَا أَنَا أَسِيرُ فِي الْجَنَّةِ إِذَا أَنَا بِنَهَرٍ حَافَتَاهُ قِبَابُ الدُّرِّ الْمُجَوَّفِ قُلْتُ مَا هَذَا يَا جِبْرِيلُ قَالَ هَذَا الْكَوْثَرُ الَّذِي أَعْطَاكَ رَبُّكَ. فَإِذَا طِينُهُ ـ أَوْ طِيبُهُ ـ مِسْكٌ أَذْفَرُ
baynamā anā asīru fī al-jannah idhā anā binaharin ḥāfatāhu qibābu ad-durri al-mujawwafi qultu mā hadhā yā jibrīlu qāla hadhā al-kawtharu adh-dhī aʿṭāka rabbuka. fa-idhā ṭīnuhu aw ṭībuhu miskun adhfaru
Transliteration generated from the Arabic vowel marks
The full narration
Narrated Anas bin Malik:The Prophet (ﷺ) said: "While I was walking in Paradise (on the night of Mi'raj), I saw a river, on the two banks of which there were tents made of hollow pearls. I asked, "What is this, O Gabriel?' He said, 'That is the Kauthar which Your Lord has given to you.' Behold! Its scent or its mud was sharp smelling musk!" (The sub-narrator, Hudba is in doubt as to the correct expression)
Source
Ṣaḥīḥ al-Bukhārī · 6581