"I saw the letter of 'Umar bin Al-Khattab to Abu Musa (in which he said): 'A caravan came to me from Ash-Sham carrying a thick black paint like the pitch that is daubed on camels. I asked them how long they cooked it, and they told me that they cooked it until it was reduced by two-third. So the bad two-third had gone, one-third to take away evil and one-third to take away the bad smell. So let those who are with you drink it."  

أَنَّهُ قَالَ قَرَأْتُ كِتَابَ عُمَرَ بْنِ الْخَطَّابِ إِلَى أَبِي مُوسَى أَمَّا بَعْدُ فَإِنَّهَا قَدِمَتْ عَلَىَّ عِيرٌ مِنَ الشَّامِ تَحْمِلُ شَرَابًا غَلِيظًا أَسْوَدَ كَطِلاَءِ الإِبِلِ وَإِنِّي سَأَلْتُهُمْ عَلَى كَمْ يَطْبُخُونَهُ فَأَخْبَرُونِي أَنَّهُمْ يَطْبُخُونَهُ عَلَى الثُّلُثَيْنِ ذَهَبَ ثُلُثَاهُ الأَخْبَثَانِ ثُلُثٌ بِبَغْيِهِ وَثُلُثٌ بِرِيحِهِ فَمُرْ مَنْ قِبَلَكَ يَشْرَبُونَهُ