سنن ابن ماجه

It was narrated from (`Ubaidullah bin `Abdullah) bin Aqram Al-Khuza`i that his father said: “I was with my father on the plain in Namirah,* when some riders passed us and made their camels kneel down at the side of the road. My father said to me: ‘Stay with your lambs until I go to those people and see what they want.’ He said: Then he (my father) went out and I came, (i.e., I came near,) then there was the Messenger of Allah (ﷺ), and the time for prayer came so I prayed with them, and I was looking at the whiteness of the armpits of the Messenger of Allah (ﷺ) every time he prostrated.”

Ibn Majah said: The people say `Ubaidullah bin `Abdullah, but Abu Bakr bin Abu Shaibah said: "The people say `Abdullah bin `Ubaidullah."
Muhammad bin Bashshar said: "`Abdur-Rahman bin Mahdi, Safwan bin `Eisa and Abu Dawud all said: 'Dawud bin Qais narrated to us, from `Ubaidullah bin `Abdullah bin Aqram, from his father, from the Prophet (ﷺ).'" With similar wording.