What is the Earliest Source and Chain of this Hadith and Athar?

>"O Allah! Guide Quraysh, for the science of the scholar that comes from them will encompass the earth. O Allah! You have let the first of them taste bitterness, so let the latter of them taste reward." >Abu Qilaba and Ahmed ibn Hanbal said that this hadith refers to Shafii 1. What is the earliest source and chain of this Hadith? 2. What is the earliest source of Abu Qilaba and Ahmed ibn Hanbal mentioning that this hadith refers to Shafii? If it's not a direct text from them, what is the chain for the athar?