What is the ruling on cutting dates before they ripen (while they are balah) and placing them in cold storage until they fully ripen, then selling them after four months?

The default ruling for selling is permissibility, and it is only prohibited in cases of harm or deception. As for selling fruit before its ripeness becomes apparent, there are two scenarios: either it is sold with the condition that it remains on the tree, in which case it is impermissible by consensus due to the prohibition of the Prophet (peace be upon him), or it is sold with the condition of immediate harvesting, in which case it is permissible by consensus, because the prohibition was out of fear of the fruit perishing.