Abu Abdillaah Al-Haakim (rahimahullaah) said: Shubah (rahimahullaah) is an Imaam of the Imaams of hadeeth at Basra (i.e. in his era) with regards to knowledge of hadeeth.  He saw Anas Ibn Maalik (radiyallaahu-anhu) and Amr Bin Salama Al-Jarmiy.  He heard (hadeeth and received knowledge) from four hundred Sheikhs amongst the Taabieen.  [Siyar A’laam An-Nubulaa:7/26]