Sahih Bukhari Volume 003, Book 044, Hadith Number 677.
Narated By Sulaiman bin Abu Muslim : I asked Abu Minhal about money exchange from hand to hand. He said, "I and a partner of mine bought something partly in cash and partly on credit." Al-Bara' bin 'Azib passed by us and we asked about it. He replied, "I and my partner Zaid bin Al-Arqam did the same and then went to the Prophet and asked him about it. He said, 'Take what was from hand to hand and leave what was on credit.'"