Is it valid to stipulate food and clothing for the laborer that belongs to someone else, if described?

Primary text

If the food and clothing specified belong to another party but are described, it is valid because the benefit is known, resembling the stipulation of known monetary wages. This becomes the property of the laborer, who may choose to consume it or not. If it is not described, it is not valid because it is unknown, unless it is stipulated due to necessity and established custom, in which case the uncertainty is accepted.