Sahih al-Bukhari 1554
Narrated Nafi`:
Whenever Ibn `Umar intended to go to Mecca he used to oil himself with a sort of oil that had no 
pleasant smell, then he would go to the Mosque of Al-Hulaita and offer the prayer, and then ride. 
When he mounted well on his Mount and the Mount stood up straight, he would proclaim the 
intention of assuming Ihram, and he used to say that he had seen the Prophet (ﷺ) doing the same.
حَدَّثَنَا سُلَيْمَانُ بْنُ دَاوُدَ أَبُو الرَّبِيعِ، حَدَّثَنَا فُلَيْحٌ، عَنْ نَافِعٍ، قَالَ كَانَ ابْنُ عُمَرَ ـ رضى الله عنهما ـ إِذَا أَرَادَ الْخُرُوجَ إِلَى مَكَّةَ ادَّهَنَ بِدُهْنٍ لَيْسَ لَهُ رَائِحَةٌ طَيِّبَةٌ، ثُمَّ يَأْتِي مَسْجِدَ الْحُلَيْفَةِ فَيُصَلِّي ثُمَّ يَرْكَبُ، وَإِذَا اسْتَوَتْ بِهِ رَاحِلَتُهُ قَائِمَةً أَحْرَمَ، ثُمَّ قَالَ هَكَذَا رَأَيْتُ النَّبِيَّ صلى الله عليه وسلم يَفْعَلُ‏.‏