Because a fish pees in his own drinking water, there is no difference between him and his entire universe. If a buddhist starts from the view of non-duality (no self / no other) then the question of (there being any difference between) an external deity and one's own mind becomes moot. I think. Praying to anything that one believes to exist outside the mind seems contrary to Buddhist teachings. On the other hand, if one is engaged the the parctice of mindful awareness when doing other activities such as chopping vegetables or sweeping the floor or whatever, then why should it matter whether the activity is an aspiration ("prayer") or cleaning a toilet? In other words, there is meditation (sammat. & vipp..) which, strictly speaking, is essentally what the Buddha taught, and then there is the question of where one's practice is when one is "off the cushion" as they say. So, can one "pray" and do so "mindfully"? It's all so terribly subjective. If you tell me that as part of your practice you pray for hungry ghosts or for people who suffer from illness or disaster, maybe that doesn't sound so bad. If I then tell you that every I day rub the tummy of a plaster buddha statue and make a wish, it sounds like a promotional scheme for a new Chinese restaurant. Speaking of restaurants, I have some friends who are Thai monks (living in the United States). Every once in a while they accept the request to conduct a blessings ceremony for the opening of a new Thai restaurant. So, now there is this idea of 'prayers' and 'aspirations' and 'affirmations' and 'blessings' and then simply motivation and intention and how they manifest as the actions of one's speech, conduct and thought. What differentiates a Buddha from someone who has (merely) ceased being attached to the temporary phenomena of our world? Does a Buddha break through all of our notions of conceptual time and space? Does anyone who becomes enlightened do this? If not, then what is enlightenement, and if so, can someone who "existed" in a body centuries ago still be generating something today that benefits people? Not arguing one way or the other---just throwing some marshmallows into the fire.