Is money earned from the uncle's cultivation of the land that the father used to cultivate for half the crop permissible?

If a father is unable to cultivate land owned by another due to imprisonment or similar circumstances, he may agree with another trustworthy person to complete its cultivation, based on a mutually agreed share of the produce, provided that the landowner did not stipulate that the father must perform the work himself. If such a condition exists, he is not permitted to have someone else take his place except with the permission of the landowner. It is stated in Hashiyat Al-Dasuqi: "It is permissible for a worker in a Musaqah agreement to employ another trustworthy worker... The permissibility is contingent on the owner of the garden not having stipulated that the worker must perform the work himself."