Mukhtasar Bukhari (Abridged) 585 — If one omits Sunnah before or after

It is narrated from Sayyiduna Amir bin Rabi’ah (may Allah be pleased with him) that he saw the Messenger of Allah (peace and blessings of Allah be upon him) performing voluntary prayers at night while traveling on his mount, regardless of which direction the mount was facing (even if it was not facing the Ka’bah).