The Creator promised the Patriarchs, Abraham, Isaac and Jacob, that their descendants would inherit the land in which all three of them had dwelled. He repeated this promise to Moses when He sent him to liberate His chosen people from Egyptian bondage and to lead them to the Promised Land.
It should be noted that in some American folk songs and spirituals the term Promised Land sometimes connotes the afterlife of Heaven. For Jews, however, the Promised Land is the Heaven on Earth promised to our ancestors.