Is a directive to purchase something on credit valid?

Primary text

The directive given by an individual to another, saying, 'Buy for me on your liability' (or: 'Borrow one thousand units for me in exchange for a measure of food, and settle the price for me from your wealth, or from the debt you owe me'), is valid. If the purchase is made on the agent's liability (dhimmah), the purchase legally belongs to the principal (muwakkil), and the price is incumbent upon the principal. If the agent settles this price using the principal's money against the principal's debt to the agent, this is treated as settling the debt to the person authorized to receive it. If the agent settles the price from their own wealth against the debt of the loan taken on the principal's behalf, it becomes a loan (*qard*) owed by the principal to the agent.