Alqama bin Qays علقمة بن قيس بن عبد الله · The Book of the Commencement of the Prayer

"I saw the Messenger of Allah (ﷺ) raise his hands until they reached the highest part of his ears, when he said the takbir, when he bowed and when he raised his head from bowing."

"The Messenger of Allah (ﷺ) said: 'The prayer is not valid if a man does not bring his backbone to rest while bowing and prostrating.'"

"Be moderate in bowing and prostration, and do not rest your forearms along the ground like a dog."