Ismail says that I asked Hazrat Sha’bi whether it is obligatory and necessary to appoint a witness when a person buys something. He replied: No, do you not see this verse of the Holy Qur’an: { فَإِنْ أَمِنَ بَعْضُکُمْ بَعْضًا } If you trust one another, then there is no harm.