Abd al-Rahman bin Mahdi (may Allah have mercy on him) says: The hadiths that Hammam (may Allah have mercy on him) narrates from Qatadah (may Allah have mercy on him) are more authentic than those of others, because he wrote them down as they were dictated.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العتق / 21377