If the purpose is help, the arrangement is a loan. The lender may recover the principal, but he cannot make an additional return a condition of the loan.
If the purpose is commercial profit, the relationship is different. The financier may participate in a lawful business arrangement and take an agreed share of the actual profit, while accepting the relevant business risk.
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The Basic Idea of Islamic Financing
If the purpose is help, the arrangement is a loan. The lender may recover the principal, but he cannot make an additional return a condition of the loan.
If the purpose is commercial profit, the relationship is different. The financier may participate in a lawful business arrangement and take an agreed share of the actual profit, while accepting the relevant business risk.