A more thorough explanation:

Definition: The Gentleman Usher of the Black Rod is an officer of the House of Lords who has various ceremonial duties. One of their important duties is to summon the members of the House of Commons to the House of Lords when a bill is to receive royal approval. This office has been around since the 14th century.

Example: When the Queen is about to give a speech in the House of Lords, the Gentleman Usher of the Black Rod is responsible for summoning the members of the House of Commons to attend the speech. They do this by walking to the House of Commons and knocking on the door three times with a black rod. This is a symbolic way of showing that the House of Lords has authority over the House of Commons.

Explanation: The example illustrates how the Gentleman Usher of the Black Rod carries out their ceremonial duties. They use a black rod to symbolize their authority and to summon members of the House of Commons to attend important events in the House of Lords. This is an important part of the British parliamentary system and helps to maintain the traditions and customs of the House of Lords.