Is a sick relative, whose illness has prevented him from working and who has no other income, deserving of zakat, given that he owns three carats of agricultural land which he left to his poor father, and a plot of land on which he built a house that his father uses as a livestock pen?

If a man gifts his land to his father, and the father takes possession of it, it exits the son's ownership, and he becomes eligible for Zakat (definition) if he does not have sufficient means for himself. However, if it was a loan (ariya) that can be reclaimed and utilized to meet his needs, then he is not eligible for Zakat, and he must reclaim it because fulfilling his own needs takes precedence over his father's needs, and retracting a loan is permissible. If the father is poor and no one is spending on him, then he is eligible for Zakat.