C137 Doubt over a piece of paper

"Brat, I knew that you would return to the hotel with that girl. When you saw this note, the thief and his wife had already left. It was indeed obtained from the Meng Clan's Elder Pavilion. This was true, but it wasn't stolen by them, but I openly took it from the Meng Clan's Elder Pavilion. You should keep this book well. As for what exactly it is, I'm not too sure either