Musannaf Ibn Abi Shayba 13:3149

Abu Bakr narrated to us, he said: Ghundar narrated to us, from Shu'bah, from Hudhayfah ibn al-Yaman, he said: I heard al-Sha'bi saying: If a man enters into a partnership with a man and he does not pay [his share of the capital], then there is no liability upon him; it is only a gift he has bestowed upon him.