Is it permissible to purchase productive farms for a number of years?

The Prophet, may Allah’s prayers and peace be upon him, forbade the sale of mu‘awamah, which is selling fruit for coming years. Selling something non-existent is invalid by consensus, and there is a نقل (reported/transmitted) consensus of Muslims on the invalidity of selling fruit for two years or similar periods. Mu‘awamah is the sale of trees for two, three, or more years.