A jeweler has relatives, friends, and customers to whom he gives loans, and even jewelry for which they do not pay the whole price and the rest is deferred. Is it permissible for the gold dealer to
complete the sale and record down the remaining sum of money on the purchaser's account, (Part No. 13; Page No. 475) or what should he do, taking into consideration that his friend refuses to buy from anyone other than him?
This sale is impermissible for it involves Riba Al-Nasi'ah (usury of delay, conditional excess for delay of payment) as mentioned in the answer to the first question. Your close relationship to the purchaser, whether he is a relative of yours, a friend for example that you give loans to if he asks for it, is not an excuse for deferring the price or part of it and not a sound reason for making such transaction.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.