Is it permissible for an agent to sell an item for less than a price stipulated by the principal?

Primary text

If the principal stipulates a specific price (*thaman*) for the item, the agent is prohibited from selling it for less than that stipulated price. If the principal gives a general authorization to sell without specifying a price, the agent may sell it for the usual market price or for more than the usual price. This view is held by Al-Shafi'i.