I've wondered for a long time how is the appearance of anonymous post vedic revealed literature explained within the traditions. 

By that I mean.for example with the tantric literature.  We have tantric texts that are dialogues between a god and his goddess usually starting with some statement like: "The God said" or "The goddess asked" etc.  and my understanding is that  tantric  texts like this have been appearing for over a thousand years. 

 Of course we explain them simply that such and such a text was written by a person or persons unknown at around such and such a date. But how do the traditions themselves explain this.  I.e all of a sudden a written text that was unknown before with the words of a god  written down usually beginnning with some statement like:śrīdevyuvāca or īśvara uvāca suddenly appeared in our world. And this happened with all this kind of revealed literature.. Do any of the texts ever say anything aboutt how and why the text will be revealed in the world of men  or do the commentators ever say how the text came to be known in the world of men..