He narrated hadeeth from many scholars, the likes of Sufyaan Ibn 'Uyainah, Hushaim Ibn Basheer, Yahyaa Ibn Sa'eed Al-Qattaan, 'Abd-ur-Rahmaan Ibn Mahdee, Wakee' and many others.
Similarly, many scholars narrated from him, such as Al-Bukhaaree and Muslim, the latter of whom reported so many hadeeth on his authority, that they number past a thousand. 
The scholars agree unanimously upon his reliability and trustworthiness (in the field of hadeeth).
Ibn Hibbaan (رحمه الله) said of him:
"He was precise and accurate in memory. And he was one of the close companions of Ahmad and Yahyaa Ibn Ma'een."
Al-Khateeb Al-Baghdaadee (رحمه الله) said:
"He was reliable, trustworthy, possessed good memory and he was precise (in narration)." 
He was born in the year 160H and died in the year 234H. May Allaah have mercy on him.
 With a fat-ha on the Noon (An "a" after the "n"). This is an ascription to a city that was near Khuraasaan, called Nasaa. People from there attribute themselves to it with "Naswee" also.
 Translator’s Note: This includes his son, Abu Bakr, Ahmad bin Abee Khaithama, may Allaah have mercy on him. He was from Baghdad. He authored the book at-Taareekh al- Kabeer.
Ad-Daraqutnee said about him:
“He was reliable and trustworthy.”
Al-Khateeb Al-Baghdaadee said:
“He was a reliable scholar, a precise Haafidh, knowledgeable of the history of people and the narrations of poetry. He studied hadeeth under Ahmad bin Hanbal and Ibn Ma’een. He died in the month of Jumaadal-Oolaa, 289H at the age of 94 years.”
 Taareekh Baghdaad (8/482).