What are the permissible modes of sale (cash or credit) for a Mudarib when the terms of the contract are specified?

Primary text

If the capital provider specifies the mode of transaction, such as 'by cash' (naqdan), 'on credit' (nasi'atan), or specifying the currency of the land or another currency, the Mudarib must adhere to it. The Mudarib is an authorized agent, and any deviation invalidates the action, similar to a general agent (wakil). Adherence to the specified terms does not prevent the primary objective of the Mudarabah, and sometimes specifying the terms seeks additional commercial advantage.