Musannaf Ibn Abi Shayba 18:1328

Abu Bakr narrated to us, he said: Jarir narrated to us, from Raqabah, from Hammad, from Ibrahim, regarding the jar that is placed on a wall and it strikes a person. He said: If the base of the wall belonged to the owner of the jar, he is not liable for what it strikes, regarding a thing that is placed upon a thing from his own property.