Al-Kāfi

Hadith 422
fasting
4ـ أَحْمَدُ بْنُ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ الْحُسَيْنِ عَنْ أَحْمَدَ بْنِ الْحَسَنِ عَنْ أَبِيهِ عَنْ عَلِيِّ بْنِ رِبَاطٍ عَنِ ابْنِ مُسْكَانَ عَنْ لَيْثٍ الْمُرَادِيِّ قَالَ سَأَلْتُ أَبَا عَبْدِ الله (عَلَيْهِ السَّلاَم) عَنِ الصَّائِمِ يَحْتَجِمُ وَيَصُبُّ فِي أُذُنِهِ الدُّهْنَ قَالَ لا بَأْسَ إِلاَّ السُّعُوطَ فَإِنَّهُ يُكْرَهُ.
4. Ahmad ibn Muhammad from has narrated from Ali ibn al-Husayn from Ahmad ibn Muhammad from ibn al-Hassan from his father from Ali ibn Ribat from ibn Muskan from Layth al-Muradiy who has said the following: “I once asked abu ‘Abd Allah (a.s.), about the case of a fasting man who applies cupping and oil in his ears. He (the Imam) said, ‘It is not harmful except sniffing snuff, which is undesirable.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī