قَالَ لِي أَبُو عَبْدِ اللَّهِ ع الثَّوْبُ النَّقِيُّ يَكْبِتُ الْعَدُوَّ وَ الدُّهْنُ يَذْهَبُ بِالْبُؤْسِ وَ الْمَشْطُ لِلرَّأْسِ يَذْهَبُ بِالْوَبَاءِ قَالَ قُلْتُ وَ مَا الْوَبَاءُ قَالَ الْحُمَّى وَ الْمَشْطُ لِلِّحْيَةِ يَشُدُّ الْأَضْرَاسَ.
“Abu ‘Abd Allah (a.s.), has said, ‘Clean and fresh clothes saddens the enemy, using oil dispels despair and combing the head removes al-Waba’.’ I then asked, ‘What is al-Waba’?’ He (the Imam) said, ‘It is fever. Combing the beard strengthens molar teeth.’”