Reference: Safahaat Mushriqah min Hayaat al-Imaam Muhammed ibn Saalih al-‘Uthaymeen – Page 161
It has been narrated:
Shaykh Ibn ‘Uthaymeen would accompany Shaykh ‘Abdur-Rahmaan as-Sa’dee – on foot – to whatever place he was invited to, and along the way he would ask his Shaykh questions for the duration of the journey until they arrived at the destination. Thereafter, the Shaykh would return whilst Shaykh ‘Abdur-Rahmaan would enter.