Islamic banking alleges the need to do good and forbid evil in the use of financial tools, particularly the prohibition of Riba and the prohibition of Gharar (risky or ambiguous sales). In Islam, one does not lend to make money, and one does not borrow to finance a business -loans are a charitable contract, which differs from a sales contract.
But, if one lends you money he or she can request the money back at any time, if you cannot repay, the repayment time is extended, if you never pay back, it becomes charity……………………………………….Full Article: Source