Al-Kāfi - Volume 6 > The Saltwort and Cyperus
Hadith #3

مُحَمَّدُ بْنُ يَحْيَى عَنْ عَلِيِّ بْنِ الْحَسَنِ بْنِ عَلِيٍّ عَنْ أَحْمَدَ بْنِ الْحُسَيْنِ بْنِ عُمَرَ عَنْ عَمِّهِ مُحَمَّدِ بْنِ عُمَرَ عَنْ رَجُلٍ عَنْ أَبِي الْحَسَنِ الْأَوَّلِ ( عليه السلام ) قَالَ مَنِ اسْتَنْجَى بِالسُّعْدِ بَعْدَ الْغَائِطِ وَ غَسَلَ بِهِ فَمَهُ بَعْدَ الطَّعَامِ لَمْ تُصِبْهُ عِلَّةٌ فِي فَمِهِ وَ لَمْ يَخَفْ شَيْئاً مِنْ أَرْيَاحِ الْبَوَاسِيرِ .

3. Muhammad ibn Yahya has narrated from Ali ibn al-Hassan ibn Ali from Ahmad ibn al-Husayn ibn ‘Umar from his uncle Muhammad ibn ‘Umar from a man who has said the following: “If one washes the outlet of his feces and his mouth after food with cyperus no illness will occur in his mouth and hewill have no fear of gases or hemorrhoid.’”