Uthman bin Sa'id al-Darimi (may Allah have mercy on him) says: I said to Yahya bin Ma'in: "Who is dearer to you regarding (the narrations of) Nafi': Malik or Ubaydullah bin Umar?" He said: "Malik." I said: "And Ayyub al-Sakhtiyani?" He said: "Malik."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العتق / 21356