Al-Mu'jam al-Awsat 2687 — I asked Sayyiduna Uqbah bin Amr

Salim al-Barrad (may Allah have mercy on him) said: I asked Sayyiduna Uqbah bin Amr (may Allah be pleased with him) about the prayer of the Messenger of Allah (peace and blessings be upon him). He stood up towards the mosque and said the takbir. Then he bowed and placed his hands on his knees, with his fingers somewhat below them, and kept his arms away from his sides; he remained in ruku' until every limb of his settled in its place. Then he stood up until every limb of his settled in its place. Then he prostrated, placing both his hands on the ground and keeping his arms away from his sides, and prostrated until every limb of his settled in its place. Then he sat (between the two prostrations) until every limb of his settled in its place. Then he made the second prostration, until he had completed four rak'ahs. Then he said: "This is how I saw the Prophet (peace and blessings be upon him) praying."
No one narrated this hadith from Mufaddal except Yahya.
This is how it is in the printed Dar al-Haramayn edition, and the editor has pointed out that the wording is the same in the manuscript too.