Musannaf Ibn Abi Shayba 3:1951

Abu Khalid al-Ahmar narrated to us, from al-A'mash, from 'Ata', from Abu 'Abd al-Rahman, who said: He used to recite the prostration (sajdah) while he was not facing the qibla and while he was walking, so he would gesture with his head, then he would say the taslim.