Regarding the dating of the Heart Sutra (remembering that the Buddha's death was around 483 BCE) : " Recent scholarship is unable to verify any date earlier than the 7th century CE." http://en.wikipedia.org/wiki/Heart_Sutra Quite apart from all of that, and the obvious similarites to some of the Pali suttas, it doesn't seem to be addressing the way that the Buddha himself actually taught about emptiness.