Sahih Bukhari Volume 2, Book 25, Hadith 1554

وَقَالَ أَبُو مَعْمَرٍ حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا أَيُّوبُ، عَنْ نَافِعٍ، قَالَ كَانَ ابْنُ عُمَرَ ـ رضى الله عنهما ـ إِذَا صَلَّى بِالْغَدَاةِ بِذِي الْحُلَيْفَةِ أَمَرَ بِرَاحِلَتِهِ فَرُحِلَتْ ثُمَّ رَكِبَ، فَإِذَا اسْتَوَتْ بِهِ اسْتَقْبَلَ الْقِبْلَةَ قَائِمًا، ثُمَّ يُلَبِّي حَتَّى يَبْلُغَ الْمَحْرَمَ، ثُمَّ يُمْسِكُ حَتَّى إِذَا جَاءَ ذَا طُوًى بَاتَ بِهِ حَتَّى يُصْبِحَ، فَإِذَا صَلَّى الْغَدَاةَ اغْتَسَلَ، وَزَعَمَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم فَعَلَ ذَلِكَ‏.‏ تَابَعَهُ إِسْمَاعِيلُ عَنْ أَيُّوبَ فِي الْغَسْلِ‏.

Narrated Nafi:'Whenever Ibn Umar(R.A.) finished his morning Salat(prayer) at Dhul-Hulaifa he would get his Rahila(mount) prepared.Then,he would ride on it, and after it had stood up straight(ready to set out),he would face Al-Qiblah (the Ka'abah at Makkah) while sitting (on his mount) and recite Talbiya.When he had reached the boundaries of the Haram(or Makkah), he would stop the recitation of Talbiyah till he reached Dhi-Tuwa(near Makkah)where he would pass the night till it dawn.After offering the morning Salat, he would take a bath.He claimed that Allah's Messenger (s.a.w.) had done the same.