Context: a rude housekeeper welcomed the speaker into the house right before leaving. He's now retelling his experience. And no, the woman did not literally committed any kind of murder, or is affiliated with any murderer.‘A sour old beldame with a face of curds welcomed us, thank you,’ he said. ‘ ”Howdy-do,” she told me, “I hope I see you alive when I come back in the morning and your dinner’s on the sideboard.” Saying which, she departed in a late-model convertible with First and Second Murderers.’
I don't get the part in bold. Is there a reference of some sort or some kind of mockery here?
Source: The Haunting of Hill House