Al-Kāfi - Volume 4 > Matters Permissible in the State of al-’ Ihram after Shower, Such as Perfume, Hunting and Others Before Talbiyah (Here I am O Lord, to obey Your command)
Hadith #4

4ـ عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ الْحَكَمِ عَنْ دَاوُدَ بْنِ النُّعْمَانِ عَنْ أَبِي أَيُّوبَ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ قَالَ قَالَ أَبُو عَبْدِ الله (عَلَيْهِ السَّلاَم) لا بَأْسَ بِأَنْ يَدَّهِنَ الرَّجُلُ قَبْلَ أَنْ يَغْتَسِلَ لِلإِحْرَامِ أَوْ بَعْدَهُ وَكَانَ يَكْرَهُ الدُّهْنَ الْخَاثِرَ الَّذِي يَبْقَى.

4. A number of our people have narrated from Ahmad ibn Muhammad from Ali ibn al-Hakam from Dawud ibn al-Nu’man from abu Ayyub from Muhammad ibn Muslim who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘It is not harmful if a man applies oil before or after taking Ghusl (bath) for Ihram.’ He (the Imam) disliked only thick oil that stays.”