Musannaf Ibn Abi Shayba 3:2713

Ghundar narrated to us, from Shu'bah, who said: I asked Hammad about a man who gathers [prayers] from two farsakhs, and he said: "No." And I asked al-Hakam, and he said: "If he comes and goes in one day, then Jumu'ah is incumbent upon him."