A harsh accusation of cruelty highlights a complete disregard for the most basic survival needs of the vulnerable. The image of an exhausted person refers specifically to someone suffering from intense thirst [ביאור שטיינזלץ]. The primary approach among commentators is that the central charge involves failing to give water to the thirsty and withholding bread from the hungry.
However, this behavior goes beyond a simple lack of compassion or a passive refusal to help. The cruelty is an active, deliberate choice. The denial of food and drink was the direct result of locking people in prison, a harsh measure that inevitably stripped these captives of any access to bread and water [מצודת דוד].