Mu'jam Kabir Tabarani 18323 — from Sayyiduna Wa'il bin Hujr; he said

Abd al-Rahman al-Yahsubi (may Allah have mercy on him) narrates from Sayyiduna Wa'il bin Hujr (may Allah be pleased with him); he said: I said: I will certainly watch the Messenger of Allah (peace and blessings be upon him). He would say the takbir when going down and when rising, and he would raise his hands, and he would give the salam to his right and to his left.