When did One Piece first mention the pirate with black beard?

When Blackbeard attacked the drum kingdom in Wapol, the former king of the fruit-swallowing drum kingdom was attacked by Blackbeard, so he abandoned his people and fled to the sea as a pirate. Here, when he first mentioned "alabaster", he told Luffy that he was chasing a man named Blackbeard, but he didn't say that Luffy first heard that he met Blackbeard before going to an empty island, and then Luffy saw Blackbeard for the first time.