Question: What is an “Earthly Hand”?

Answer: When East player (the only player with 14 tiles) has Mah Jongg after the Charleston, it is called an “Earthly Hand.” If this occurs, it is considered a self-picked Mah Jongg and the winner is paid double by all players. Also see ID102.

Source:  Mah Jongg Made Easy 2020, page 14