On Guru Granth Sahib: Who is the thief? What is it to cut off his hands?

The following is an excerpt from a samvaad (dialogue) session with Acharya Prashant.

जे मोहाका घरु मुहै घरु मुहि पितरी देइ ॥
Je mohākā gẖar muhai gẖar muhi piṯrī ḏee.
The thief robs a house, and offers the stolen goods to his ancestors.