What is Asteya
From Living the Bhagavad Gita (p.150):
Asteya – non-stealing – is obvious: If everybody’s “us” who are you going to steal from? Are you going to rip yourself off?
… So in order to steal, you have to see your victim as “other”. That means stealing takes us deeper into the illusion of me/you, which is the illusion of identity, which is the illusion of separation. That, from a spiritual point of view, is why non-stealing is part of the practice of ashtanga yoga; it’s not because of our usual ideas about morality, it’s because in order to steal we have to turn the other person into “them”, which rules out our seeing them as “us”.
… to avoid separating ourselves from other people, we stop ripping them off. … It’s not just the physical stuff, like not stealing somebody’s wallet. Practicing asteya includes things like not accepting praise and not taking credit for somebody else’s ideas. It means in the very broadest sense possible that you don’t appropriate anything, material or otherwise, that isn’t rightfully yours. That’s asteya.