From the foundation of the world

I am researching the Biblical phrase "from the foundation of the world". As a point of reference, Matt 13:35 quotes Psalm 78:2 as "I will utter things which have been kept secret from the foundation of the world". However, Psalms simply states "I will utter dark sayings of old". It seems that the former may be an idiomatic, somewhat hyperbolic expression rather than a factual, chronological reference to Genesis 1. What thinkest thou?

I think that they are, like other phrases ('from the dawn of time', or whatever), rather fanciful ways of saying 'I will tell you some old stories'.

DFG